Trace require callers

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

Annotations already cover read-only/idempotent/non-destructive/openWorld, so the description earns credit for adding context beyond them: cost=medium, a required precondition (active-client), and declared outputs (bounded-event-snapshot, operation-receipt). These are useful traits the structured fields do not carry.

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?

The purpose is front-loaded, but the metadata block is template-y and partly redundant with annotations ('Safety: read-only' and 'idempotency=read-only' restate readOnlyHint/idempotentHint). The failure-handling sentence is boilerplate that adds little for an agent that already has tool-schema available.

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 2-param, all-optional, read-only scan with no output schema, the description covers phase, precondition, cost, and output kinds—enough for an agent to invoke it confidently. Only the lack of sibling differentiation and parameter nuance keeps it from being fully complete.

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 both parameters are already documented, making 3 the baseline. The description restates the signature ('{ limit: any?, threadContext: number? }') without adding syntax, format, or default detail beyond the schema—in fact its 'any?' for limit is less precise than the schema's number/default 80.

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 and resource: 'Find functions that reference require' plus the mechanism ('via getgc scan') and the location ('in constants/source'). This clearly distinguishes it from generic GC scans, though it does not name a specific sibling to route away from.

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 contextual signals ('Phase: observe', 'Requires: active-client') that imply when it is callable, and a fallback pointer ('On failure: inspect tool-schema'). But it never states when to prefer this over alternatives like find-string-xrefs or find-constants-xref, so routing is left to inference.

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