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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds useful behavioral context: it accepts a `#section` suffix, and it maps specific id prefixes to different content types (markdown guide, OpenAPI endpoint, response model). This goes beyond the schema's generic 'id returned by search'.

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 a single, dense sentence that front-loads the core purpose ('Full text for one id from `search`') and then efficiently enumerates the accepted id forms. Every clause earns its place; there is no filler or repetition of schema content.

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 single-parameter read tool with an output schema and readOnly/idempotent annotations, the description is nearly complete. It explains the id format variants and even notes special cases like `docs/changelog` and `docs/pricing`. The only minor gap is that it doesn't describe error behavior for invalid ids, but that is not essential given the output schema and simple parameter.

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 the `id` parameter. The description adds meaningful format details (e.g., `docs/<slug>`, `op/<operationId>`, `schema/<name>`) that the schema does not provide, but since the schema already covers the basic semantics, a baseline 3 is appropriate.

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 names a specific verb ('Fetch') and resource ('one id from `search`'), then enumerates the three accepted id forms (`docs/<slug>`, `op/<operationId>`, `schema/<name>`) with concrete examples. This clearly distinguishes it from siblings like `search` and `get_endpoint`.

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 description explicitly states the tool is for fetching full text for one id returned by `search`, which implies it should be used after `search` and not for listing or searching. It does not explicitly name alternatives or exclusions, but the id-source constraint and the sibling set make the usage context clear.

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