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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description goes further with return ordering, default and max result counts, the fact that `text` is only a short snippet, and the error/empty-result semantics — all beyond what annotations provide. It stops short of auth or rate-limit context, so not a full 5.

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 purpose, then return shape, then a concrete example, then edge-case behavior, then the OpenAPI link. Dense but every sentence carries distinct information with no filler or repetition.

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 correctly compensates by spelling out the JSON return shape ({results: [{id, title, url, section, text}]}) and ordering. Error and empty-result behavior plus the search-to-fetch path make the definition self-sufficient for correct invocation.

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 and the schema already documents limit, query, and section. The description adds value with a concrete worked example combining `query` and `section`, plus the actionable tip to drop `section` on no-match, which clarifies the section filter's role beyond the enum list.

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+resource ('Search docs.bithuman.ai') and enumerates the content covered (avatar SDKs, REST API, deployment, models, pricing). It explicitly distinguishes itself from the sibling by noting that `fetch` is what you use for the whole page once you have an `id`.

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 states when the tool works and how to recover from failure: empty query is an error, no match returns an empty list and you should try fewer/other words or drop `section`. It also routes the agent to `fetch` as the follow-up for full page content, giving a clear search-then-fetch workflow.

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