title: Tool Studio Observability description: In-process tool execution observability - JS sandbox and local @Tool methods, latency p50/p95/p99, error rate, and sandbox guard-block counts.

Tool Studio

Tool Studio - counts in-process Spring AI tool callbacks. When chat traffic routes through the built-in MCP server (the default exposure path), tool spans carry network.transport=tcp and surface in MCP Servers instead - so a busy chat session can still show 0 here. The Sandbox guard blocks KPI ties this dashboard to the prevention layer in Safety Architecture regardless of where the tool was routed.

Purpose - observe in-process tool execution: the JS-sandbox tools authored in Tool Studio, every Spring AI @Tool method, anything the agent calls without leaving the JVM. Cross-references the sandbox prevention layer through the sandbox.guard.blocked counter.

When to look here

• "Did the agent's tool selection finally trigger the expected searchWikipedia call?" - Top tools horizontal bar.
• "Why is my own in-process tool slow?" - Tool latency p50 / p95 / p99.
• "How often is the sandbox actually blocking unsafe actions?" - Sandbox guard blocks counter + chart (zero is healthy; sustained non-zero means agent is repeatedly trying something the sandbox denies).
• "What Risk Level posture is the running tool catalog?" - Sandbox level histogram (L0 / L3 / L4 / L5 distribution).
• "Are tools failing more than they used to?" - Error rate KPI + the Tool calls / minute trend line.

Span filter

spring.ai.tool spans where mcp.method.name is absent (in-process).

Controls

All dashboards share the Observability global settings - time window, refresh interval, custom range. Tool Studio has no tab-specific controls beyond those.

KPI cards (six)

Card	Shows	Source
Traces with tools	Number of chat turns that called at least one in-process tool	TraceRecord where any child span is spring.ai.tool without mcp.method.name
Total tool calls	Count of all in-process tool spans	Sum of qualifying spans
Distinct tools	Number of unique tool names called	set(spring.ai.tool.definition.name) size
p95 latency	95th-percentile in-process tool duration	Span duration distribution
Error rate	Percentage of tool spans with status ERROR	Span status
Sandbox guard blocks	Cumulative sandbox.guard.blocked counter	MeterRegistry counter incremented by the sandbox at each block

The Sandbox guard blocks KPI is the concrete bridge to the Safety layer. See Safety Architecture → AI Agent Tool Safety for what triggers a block and Observability Architecture → Foundation for behavioural controls for how this counter ties Sandbox prevention to Observability visibility.

Charts (five)

Chart	Type	Reading
Tool calls / minute	Stacked bar (top 4 tools), in-process spans/min	Spike → agent in a tool-heavy phase; sustained zero with chat traffic → tools not being selected (check Top tools below)
Tool latency p50 / p95 / p99	Multi-line, ms	Diverging p99 from p50 → tail-latency regression in one tool
Top tools	Horizontal bar (top 8 by call count)	The most-called tool head; helps spot accidental tool selection
Sandbox level	Histogram across L0 / L3 / L4 / L5 by call	L0 = safest baseline; high L5 traffic warrants per-tool review
Sandbox guard blocks	Horizontal bar (lifetime), by category / reason	Cluster of blocks → agent attempting forbidden action repeatedly (e.g. SSRF probe)

Cross-references

• Safety Architecture - sandbox layers, Risk Level, what triggers a guard block
• Tool Studio (feature) - how in-process tools are authored
• MCP Servers - sibling tab for the same shape of data, externally routed
• Observability Architecture → Tool and MCP observability - McpToolObservationFilter injection mechanism