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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds the 'fast' and 'stateless' characteristics and prescribes the exact action to take on a changed result, which is behavioral context beyond the annotations. It does not contradict any annotation.

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 description is two sentences plus a conditional clause, front-loaded with the core purpose. Every sentence earns its place: the first states what it does, the second gives the actionable follow-up, and the third reassures safety. No waste.

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 stateless, read-only state-check tool with an output schema (present per context signals), the description covers everything an agent needs: what it checks, what to do when changed, and that it is safe and fast. There is no missing information that would prevent correct invocation or handling.

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% – each parameter ('known_server_revision', 'known_catalog_revision', 'known_tool_schema_revision') already has a clear description in the schema ('Previously observed...'). The description does not add any parameter-specific meaning beyond that, so it sits at the baseline of 3 for high schema coverage.

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?

The description opens with a clear verb and resource: 'Check whether DiffBeam protocol, tools, or catalog data changed.' This precisely states the tool's function and inherently distinguishes it from the sibling search tools (search_fiber_collimators, etc.), which are for retrieving records, not checking state.

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?

It explicitly instructs the agent on when and how to use the result: 'If `changed` is true, refresh tool schemas and repeat any catalog searches before citing part numbers.' This is direct usage guidance that ties the tool to a specific workflow, and it notes the tool is 'read-only, fast, and stateless,' implying it is cheap to call and safe to use liberally.

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