Add Tools Skill

You are an expert at creating tool configurations for Sim integrations. Your job is to read API documentation and create properly structured tool files.

Your Task

When the user asks you to create tools for a service:

1. Use Context7 or WebFetch to read the service's API documentation
2. Create the tools directory structure
3. Generate properly typed tool configurations

Hard Rule: No Guessed Response Schemas

If the docs do not clearly show the response JSON for a tool, you MUST tell the user exactly which outputs are unknown and stop short of guessing.

• Do NOT invent response field names
• Do NOT infer nested paths from nearby endpoints
• Do NOT guess array item shapes
• Do NOT write transformResponse against unverified payloads

If the response shape is unknown, do one of these instead:

1. Ask the user for sample responses
2. Ask the user for test credentials so you can verify live responses
3. Implement only the endpoints whose outputs are documented
4. Leave the tool unimplemented and explicitly say why

Directory Structure

Create files in apps/sim/tools/{service}/:

tools/{service}/
├── index.ts      # Barrel export
├── types.ts      # Parameter & response types
└── {action}.ts   # Individual tool files (one per operation)

Tool Configuration Structure

Choose the execution boundary first

Every tool must use exactly one of these configurations:

• In-process operation (preferred): use InternalToolConfig when the executor and the implementation run in the same Sim process/trust/runtime plane. Materialize typed operation.input, implement the handler under apps/sim/lib/internal/{service}/execute-tool.ts, and register every tool ID in apps/sim/lib/internal/tool-operations/registry.server.ts.
• External provider request: use ToolConfig.request only when the URL is an absolute external HTTP(S) provider endpoint.

Never set a tool URL to /api/..., construct an absolute URL back to Sim, declare request.internal, add a directExecution property (it fails bun run check:tool-request-boundary), import a route module, or create an API route merely to normalize files, authorize access, or reuse server code. A real browser/API route may remain as a thin adapter, but the route and the tool must call the same operation directly. A true cross-process/capability boundary uses an explicit server client and is not disguised as a tool self-hop.

For protected Sim resources, the internal handler calls the domain's authorized application use case with trusted execution context; use the migrate-application-operation skill.

External provider request

Use this structure only for an absolute external provider API:

import type { {ServiceName}{Action}Params } from '@/tools/{service}/types'
import type { ToolConfig } from '@/tools/types'

interface {ServiceName}{Action}Response {
  success: boolean
  output: {
    // Define output structure here
  }
}

export const {serviceName}{Action}Tool: ToolConfig<
  {ServiceName}{Action}Params,
  {ServiceName}{Action}Response
> = {
  id: '{service}_{action}',           // snake_case, matches tool name
  name: '{Service} {Action}',         // Human readable
  description: 'Brief description',   // One sentence
  version: '1.0.0',

  // OAuth config (if service uses OAuth)
  oauth: {
    required: true,
    provider: '{service}',            // Must match OAuth provider ID
  },

  params: {
    // Hidden params (system-injected, e.g. the OAuth accessToken)
    accessToken: {
      type: 'string',
      required: true,
      visibility: 'hidden',
      description: 'OAuth access token',
    },
    // User-only params (credentials, api key, IDs user must provide)
    someId: {
      type: 'string',
      required: true,
      visibility: 'user-only',
      description: 'The ID of the resource',
    },
    // User-or-LLM params (everything else, can be provided by user OR computed by LLM)
    query: {
      type: 'string',
      required: false,                // Use false for optional
      visibility: 'user-or-llm',
      description: 'Search query',
    },
  },

  request: {
    url: (params) => `https://api.service.com/v1/resource/${params.id}`,
    method: 'POST',
    headers: (params) => ({
      Authorization: `Bearer ${params.accessToken}`,
      'Content-Type': 'application/json',
    }),
    body: (params) => ({
      // Request body - only for POST/PUT/PATCH
      // Trim ID fields to prevent copy-paste whitespace errors:
      // userId: params.userId?.trim(),
    }),
  },

  transformResponse: async (response: Response) => {
    const data = await response.json()
    return {
      success: true,
      output: {
        // Map API response to output
        // Use ?? null for nullable fields
        // Use ?? [] for optional arrays
      },
    }
  },

  outputs: {
    // Define each output field
  },
}

In-process operation

import type { InternalToolConfig } from '@/tools/types'

export const {serviceName}{Action}Tool: InternalToolConfig<
  {ServiceName}{Action}Params,
  {ServiceName}{Action}Response
> = {
  id: '{service}_{action}',
  name: '{Service} {Action}',
  description: 'Brief description',
  version: '1.0.0',
  params: {
    // Same canonical metadata as an external tool.
  },
  operation: {
    input: (params) => ({
      // Map resolved tool params into the typed semantic operation input.
    }),
  },
  outputs: {
    // Define each output field.
  },
}

The registered handler accepts InternalToolOperationCall, validates request.input, uses only trusted request.context for authority, forwards request.signal, and returns the same bounded Response contract expected by the tool executor. It has no URL, method, request headers, fetch fallback, or caller-controlled _context authority.

Critical Rules for Parameters

Visibility Options

• 'hidden' - System-injected (OAuth tokens, internal params). User never sees.
• 'user-only' - User must provide (credentials, api keys, account-specific IDs)
• 'user-or-llm' - User provides OR LLM can compute (search queries, content, filters, most fall into this category)

Parameter Types

• 'string' - Text values
• 'number' - Numeric values
• 'boolean' - True/false
• 'json' - Complex objects (NOT 'object', use 'json')
• 'file' - Single file
• 'file[]' - Multiple files

Required vs Optional

• Always explicitly set required: true or required: false
• Optional params should have required: false

Resolved Secrets and Provenance Boundaries

Classify every request field before implementing the tool.

This is opt-in, not a blanket integration migration. Add a model-input declaration only when the service's official documentation or an unambiguous local execution path proves that the exact field is consumed by an AI model. If that cannot be established, preserve existing tool behavior and leave the field unannotated.

• Ordinary provider/API input: leave it unchanged. Explicit {{...}} references resolve and are sent with their normal request semantics. A URL, domain, resource ID, control field, or opaque payload is not model-visible merely because the provider is AI-backed or may process the referenced resource later.
• Text or structured content consumed by an AI model: declare request.modelInput for an external provider request or operation.modelInput for an in-process operation, with mode: 'project' and select only the exact model-visible fields. The shared executor replaces activated Sim secrets with canonical {{NAME}} labels before request formatting. For nested or JSON-string fields, use a small shared selector plus applyProjected; verify that selecting the rebuilt params reproduces the projected selection.
• Serialized model content sent directly to an external provider: include the serialized top-level param in request.modelInput. Project the private copy before the existing request formatter parses it; keep formatter behavior deterministic when a whole-value placeholder is not valid in the serialized grammar. Do not introduce a second hard-rejection path.
• Opaque model input owned by an in-process operation such as inline audio, image, video, or document bytes: add privateInputPaths to the mode: 'project' operation model-input declaration, or use mode: 'private-provenance' with inputPaths when there is no textual projection (see the modelInput union in apps/sim/tools/types.ts). Do not select storage keys, paths, signed URLs, or ordinary remote URLs as byte provenance; the owning operation must authorize stored bytes independently at model egress. The operation must call validateOpaqueModelInputProvenance before downloading or sending content to the model and must apply the workspace-file provenance guard before reading a persisted workspace file.
• Sim-owned durable storage or internal execution handoff that can later enter a workflow/model (table cells, Agent memory, knowledge documents/chunks, workspace-file contents, or child-workflow input): transport encrypted field-scoped provenance with operation.secretProvenance. The operation validates the exact selection and trusted scope, then persists, imports, or propagates it at the owning boundary. Preserve shared legacy behavior for rows/files whose provenance marker is NULL; never invent a tool-local migration rule.

Hard rules:

• Never substitute secret plaintext into source or serialize plaintext provenance.
• Never hand-roll private provenance headers/envelopes; the shared executeTool boundary owns transport and strips private metadata from functional results.
• Never attach private provenance to an external URL. Project proven model-visible external fields with request.modelInput; otherwise preserve ordinary request semantics. Use a registered in-process operation when encrypted provenance must cross the boundary.
• Never sanitize arbitrary third-party tool results. Projection applies only to secrets activated by Sim's resolved-secret provenance for that execution/tool call.
• Do not add provenance merely because a value is persisted, returned by a tool, or appears in a filename. Require a concrete Sim {{...}} resolution path and a later model/log boundary. If an unsupported field can resolve a secret but does not justify durable tracking (for example a file_write path), reject it at that exact ingress.
• At diagnostic boundaries, project only values carrying execution-scoped provenance. Ordinary provider responses, filenames, URLs, and errors remain unchanged when Sim did not resolve a secret into them.

Add focused tests covering named projection, ordinary identical text without provenance, nested and serialized shape handling, unchanged ordinary external inputs, malformed/incomplete private metadata failing closed, headerless legacy requests, and absence of private metadata in the public tool result. For durable sinks, also cover legacy NULL markers, exact-empty new writes, tracked secret writes, stale/missing sidecars, and scope isolation.

Critical Rules for Outputs

File Downloads and Generated Files

Internal operations return createInternalToolFileResult / createInternalToolFilesResult from lib/internal/tool-operations/file-result.ts with bounded Buffers and a callback that places the stored descriptors in the response. Their handlers preserve this result through dispatch, using InternalToolOperationHandler<InternalToolOperationResult>. Do not serialize file bytes as base64 JSON: the executor's 10 MiB response cap runs before ordinary file postprocessing or large-value externalization. The shared executor stores files using trusted run or Copilot ownership.

External endpoints that return raw binary files explicitly declare request.responseType: 'binary' and return output.file with { name, mimeType, data: buffer, size } from transformResponse. The executor applies the bounded file-transfer budget and persists the descriptor. This opt-in is for raw binary responses, not provider JSON containing base64 or tools that fetch attachments later. Keep provider-specific limits and bounded reads; a file declaration is not permission to enlarge arbitrary JSON responses.

Attachment readers that download files inside transformResponse need their own bounded reads: the first response cap does not cover subsequent fetches. Accept ToolResponseContext as the third transform argument, forward its signal, and share one AttachmentDownloadBudget across sequential downloads. Prefer raw provider endpoints over base64 metadata. Return the same file object in the declared file / file[] output and nested message associations; FileToolProcessor stores it once and replaces every alias with the same UserFile in both workflow and Copilot execution.

Preserve stored UserFile fields (id, key, url, context, type, name, size) in transforms; rebuilding the old { name, mimeType, data, size } shape discards the reference. File outputs do not need duplicate inline text/base64 aliases; the file system handles content materialization. When an existing tool explicitly exposes content aliases in its contract, preserve its legacy version and use the existing block/tool version pattern for a file-only output. Test a file over 10 MiB through executor admission, single persistence, trusted ownership, and the unchanged JSON cap. Avoid adding top-level filename, size, MIME type, URL, or success fields that merely repeat the canonical file or tool result; keep additional provider fields only when they convey distinct information.

Output Types

• 'string', 'number', 'boolean' - Primitives
• 'json' - Complex objects (use this, NOT 'object')
• 'array' - Arrays with items property
• 'object' - Objects with properties property

Optional Outputs

Add optional: true for fields that may not exist in the response:

closedAt: {
  type: 'string',
  description: 'When the issue was closed',
  optional: true,
},

Typed JSON Outputs

When using type: 'json' and you know the object shape in advance, always define the inner structure using properties so downstream consumers know what fields are available:

// BAD: Opaque json with no info about what's inside
metadata: {
  type: 'json',
  description: 'Response metadata',
},

// GOOD: Define the known properties
metadata: {
  type: 'json',
  description: 'Response metadata',
  properties: {
    id: { type: 'string', description: 'Unique ID' },
    status: { type: 'string', description: 'Current status' },
    count: { type: 'number', description: 'Total count' },
  },
},

For arrays of objects, define the item structure:

items: {
  type: 'array',
  description: 'List of items',
  items: {
    type: 'object',
    properties: {
      id: { type: 'string', description: 'Item ID' },
      name: { type: 'string', description: 'Item name' },
    },
  },
},

Only use bare type: 'json' without properties when the shape is truly dynamic. Unknown is not the same as dynamic — see the Hard Rule above.

Critical Rules for transformResponse

Handle Nullable Fields

ALWAYS use ?? null for fields that may be undefined:

transformResponse: async (response: Response) => {
  const data = await response.json()
  return {
    success: true,
    output: {
      id: data.id,
      title: data.title,
      body: data.body ?? null,           // May be undefined
      assignee: data.assignee ?? null,   // May be undefined
      labels: data.labels ?? [],         // Default to empty array
      closedAt: data.closed_at ?? null,  // May be undefined
    },
  }
}

Never Output Raw JSON Dumps

DON'T do this:

output: {
  data: data,  // BAD - raw JSON dump
}

DO this instead - extract meaningful fields:

output: {
  id: data.id,
  name: data.name,
  status: data.status,
  metadata: {
    createdAt: data.created_at,
    updatedAt: data.updated_at,
  },
}

Types File Pattern

Create types.ts with interfaces for all params and responses:

import type { ToolResponse } from '@/tools/types'

// Parameter interfaces
export interface {Service}{Action}Params {
  accessToken: string
  requiredField: string
  optionalField?: string
}

// Response interfaces (extend ToolResponse)
export interface {Service}{Action}Response extends ToolResponse {
  output: {
    field1: string
    field2: number
    optionalField?: string | null
  }
}

Index.ts Barrel Export Pattern

// Export all tools
export { serviceTool1 } from './{action1}'
export { serviceTool2 } from './{action2}'

// Export types
export * from './types'

Registering Tools

After creating tools:

1. Import tools in apps/sim/tools/registry.ts
2. Add to the tools object with snake_case keys (alphabetically):

import { serviceActionTool } from '@/tools/{service}'

export const tools = {
  // ... existing tools ...
  {service}_{action}: serviceActionTool,
}

3. Regenerate the tool metadata artifacts:

bun run tool-metadata:generate

Client code reads a tool's params/outputs from generated metadata rather than importing the registry, so a tool you add, change or remove is invisible to the UI until these are regenerated — and CI fails on stale artifacts. Commit the result. See .agents/skills/tool-registry-boundary/SKILL.md.

Wiring Tools into the Block (Required)

After registering in tools/registry.ts, you MUST also update the block definition at apps/sim/blocks/blocks/{service}.ts. This is not optional — tools are only usable from the UI if they are wired into the block.

1. Add to tools.access

tools: {
  access: [
    // existing tools...
    'service_new_action',   // Add every new tool ID here
  ],
  config: { ... }
}

2. Add operation dropdown options

If the block uses an operation dropdown, add an option for each new tool:

{
  id: 'operation',
  type: 'dropdown',
  options: [
    // existing options...
    { label: 'New Action', id: 'new_action' },   // id maps to what tools.config.tool returns
  ],
}

3. Add subBlocks for new tool params

For each new tool, add subBlocks covering all its required params (and optional ones where useful). Apply condition to show them only for the right operation, and mark required params with required:

// Required param for new_action
{
  id: 'someParam',
  title: 'Some Param',
  type: 'short-input',
  placeholder: 'e.g., value',
  condition: { field: 'operation', value: 'new_action' },
  required: { field: 'operation', value: 'new_action' },
},
// Optional param — put in advanced mode
{
  id: 'optionalParam',
  title: 'Optional Param',
  type: 'short-input',
  condition: { field: 'operation', value: 'new_action' },
  mode: 'advanced',
},

4. Update tools.config.tool

Ensure the tool selector returns the correct tool ID for every new operation. The simplest pattern:

tool: (params) => `service_${params.operation}`,
// If operation dropdown IDs already match tool IDs, this requires no change.

If the dropdown IDs differ from tool IDs, add explicit mappings:

tool: (params) => {
  const map: Record<string, string> = {
    new_action: 'service_new_action',
    // ...
  }
  return map[params.operation] ?? `service_${params.operation}`
},

5. Update tools.config.params

Add any type coercions needed for new params (runs at execution time, after variable resolution):

params: (params) => {
  const result: Record<string, unknown> = {}
  if (params.limit != null && params.limit !== '') result.limit = Number(params.limit)
  if (params.newParamName) result.toolParamName = params.newParamName  // rename if IDs differ
  return result
},

6. Add new outputs

Add any new fields returned by the new tools to the block outputs:

outputs: {
  // existing outputs...
  newField: { type: 'string', description: 'Description of new field' },
}

7. Add new inputs

Add new subBlock param IDs to the block inputs section:

inputs: {
  // existing inputs...
  someParam: { type: 'string', description: 'Param description' },
  optionalParam: { type: 'string', description: 'Optional param description' },
}

Block wiring checklist

• New tool IDs added to tools.access
• Operation dropdown has an option for each new tool
• SubBlocks cover all required params for each new tool
• SubBlocks have correct condition (only show for the right operation)
• Optional/rarely-used params set to mode: 'advanced'
• tools.config.tool returns correct ID for every new operation
• tools.config.params handles any ID remapping or type coercions
• New outputs added to block outputs
• New params added to block inputs

V2 Tool Pattern

If creating V2 tools (API-aligned outputs), use _v2 suffix:

• Tool ID: {service}_{action}_v2
• Variable name: {action}V2Tool
• Version: '2.0.0'
• Outputs: Flat, API-aligned (no content/metadata wrapper)

Checklist Before Finishing

• All tool IDs use snake_case
• Chose exactly one boundary: registered InternalToolConfig.operation or absolute external HTTP(S) ToolConfig.request
• No tool request points to /api/..., constructs a URL back to Sim, or declares request.internal
• No tool declares directExecution; in-process work uses a registered operation
• All params have explicit required: true or required: false
• All params have appropriate visibility
• All nullable response fields use ?? null
• All optional outputs have optional: true
• No raw JSON dumps in outputs
• Types file has all interfaces
• Index.ts exports all tools and re-exports types (export * from './types')
• Tools registered in tools/registry.ts
• bun run tool-metadata:generate run and the regenerated artifacts committed
• bun run scripts/generate-docs.ts run and the refreshed docs committed — the integration's docs page is rendered from each tool's description, params, and outputs, and CI's bun run docs:check fails on stale pages
• Block wired: tools.access, dropdown options, subBlocks, tools.config, outputs, inputs
• Model, durable-storage, and internal-execution boundaries use the shared provenance mechanisms only where a concrete Sim {{...}} resolution path requires them
• Ordinary third-party inputs/results remain unchanged and private metadata never leaves Sim

Final Validation (Required)

Before finishing, validate each tool file against the API docs:

1. Re-read each tool file you created
2. Cross-reference with the API docs to verify:
   • All required params are marked required: true
   • All optional params are marked required: false
   • Param types match the API (string, number, boolean, json)
   • For external tools, request URL, method, headers, and body match the provider API spec
   • For internal tools, operation.input matches the handler schema and the handler is registered with no HTTP fallback
   • transformResponse extracts the correct fields from the API response
   • All output fields match what the API actually returns
   • No fields are missing from outputs that the API provides
   • No extra fields are defined in outputs that the API doesn't return
   • Every output field and JSON path is backed by docs or live-verified sample responses
3. Verify consistency across tools:
   • Shared types in types.ts match all tools that use them
   • Tool IDs in the barrel export match the tool file definitions
   • Error handling is consistent (error checks, meaningful messages)
4. If any response schema is still unknown, explicitly tell the user instead of guessing