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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered. The description adds only that the response includes guide entries plus canonical source links, which is partly redundant with the output schema; no error or lookup-failure behavior is disclosed.

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?

One sentence, front-loaded with the verb and result, with the prerequisite clause trailing. No filler words.

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 one-parameter lookup with an output schema and full annotation coverage, the description is largely sufficient. It stops short of noting behavior for unknown or stale IDs, a minor gap for a detail-fetch tool.

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 coverage is 100% and the single parameter is already described as 'Exact bird ID'. The description adds real meaning by specifying provenance — the ID must come from search_birds — which clarifies that fuzzy names or partial matches are invalid inputs.

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 ('Get') and resource ('complete guide entry and canonical source links') with clear scope. Naming 'an exact bird ID from search_birds' implicitly distinguishes this from search_birds (discovery) and list_families (browsing), so an agent can route without opening schemas.

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?

The phrase 'exact bird ID from search_birds' establishes the prerequisite workflow: obtain an ID via search_birds first, then fetch details. It does not explicitly state exclusions or what to do if no exact ID is available, keeping it below a 5.

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