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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real return-value context — the original prompt text, translation, blanks, model, video, and creator credit — plus the note that a language code causes the translated prompt to be included, which is behavior an agent cannot infer from annotations.

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?

A single sentence, front-loaded with the core action and followed by the payload enumeration. It is dense but every clause carries information; the trailing list of returned fields is the only mildly heavy portion.

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?

There is no output schema, so the description carries the return-value burden and does so by enumerating the fields an agent receives. Combined with annotations covering safety and the fully documented two-parameter schema, an agent has everything needed to call this correctly.

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%, and the description largely restates what the schema already says about 'id' (search result or page address) and 'language' (adds the translated prompt). It adds no format details, error behavior for a bad id, or id-validation guidance beyond the schema. 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 opens with a specific verb and resource — 'Returns one prompt in full' — and names the two valid id sources ('an id given by search or the address of a prompt page'), which links it to the sibling 'search'. It is clear what the tool does despite the opaque name 'fetch', though it never explicitly contrasts itself with 'list_options' or states that it is a single-item retrieval vs. the list-oriented siblings.

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?

Usage context is stated: the id comes from a prior search result or from a prompt page URL, which tells an agent the expected call sequence. There are no exclusions or anti-patterns (e.g., when to use search instead of fetching by id), so it falls short of the top score.

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