Scan closures by name

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, and 'Safety: read-only' merely repeats that. The description does add non-annotation context (cost=high, requires active-client, produces bounded-candidates, fallback to tool-schema on failure), which is genuinely useful, but the additions are terse labels rather than explanatory behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose is front-loaded, which is good, but the text is a dense run-on of colon-delimited metadata and the 'Signature: {...}' block simply duplicates the input schema, wasting space without adding information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only observe tool with no output schema, the description covers purpose, preconditions and cost, but leaves the output shape vague ('bounded-candidates') and says nothing about ranking/ordering or what a bounded result actually contains, deferring everything to tool-schema on failure.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents every parameter fully. The description only re-lists the signature with types ('nameQuery: string, limit: any?...'), which adds no meaning beyond the schema; baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Find getgc closures') and the exact filter mechanism ('debug name contains a target substring'), which self-differentiates it from the sibling scan-closures-by-source. It stops short of explicitly naming that sibling, so it is clear but not fully sibling-routing.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides partial context ('Phase: observe; cost=high', 'Requires: active-client') that implies when the tool is appropriate, but gives no explicit when-not guidance and never names an alternative tool to use instead (e.g., scan-closures-by-source or search-gc-value).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.