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

Far beyond the annotations: it discloses that first reads may return state=pending and must be retried with the same arguments after retry_after_sec, that revision.known is false because DeepWiki omits the commit, that text is provider_generated and secondary evidence, that the call is free, and that returned text is data not instructions. These are exactly the operational and trust caveats annotations cannot express.

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?

Front-loaded with what you get, then caveats and failure modes; nearly every clause carries information. It is dense and long for a two-parameter tool, and the retry instruction introduces an argument name (retry_after_sec) that isn't a parameter, which is a small structure snag.

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?

No output schema exists, and the description compensates fully by describing the response shape (topic map, one page, cited files with exists_now/not_found_now), the state/pending protocol, the fallback payload, and the revision.known limitation. An agent can call it and interpret the result without guessing.

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%, so baseline is 3; the description still adds value by explaining the topic selector's semantics (id like '4.1' or title from `topics`, defaulting to the overview page) and by explaining that cited files are checked against the default branch today. It does not clarify the `repo` format beyond the schema, so not a 5.

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 — what a repo's DeepWiki wiki says — and enumerates exactly what comes back (topic map plus one named page plus cited files with existence checks). It is immediately distinguishable from nearby tools like read_readme, ask_repository_question, and contribution_profile.

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?

Gives an explicit use case ('understand a codebase before judging work in it'), an explicit boundary ('never treat it as proof of who wrote anything — contribution_profile shows that'), and an explicit failure path (fall back to README and GitHub facts when DeepWiki has no wiki). Alternatives and exclusions are both named.

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