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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds no further behavioral detail such as rate limits, authentication needs, or output limitations, but for a simple read-only suggestion tool this is acceptable.

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 succinct sentence that covers purpose and an important exclusion with no filler. It is well-suited to be read quickly by an agent.

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, read-only suggestion tool with an output schema, the description together with annotations is fully sufficient. The agent knows what the tool does, what it doesn't do, what input to provide, and that it is safe to call.

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 keyword parameter description already includes valuable negative constraints like not passing links, user IDs, or page_token. The tool description itself adds no additional parameter semantics, so the baseline of 3 applies.

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 clearly states the operation: retrieving Bilibili search box suggestion words based on a keyword. It also differentiates itself from sibling search tools by explicitly stating it is not for searching users or content.

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 gives an explicit when-not-to-use condition: not for searching users or content. It implies the tool is for autocomplete-style suggestions, but it does not name the alternative sibling tools such as bilibili_search_users or bilibili_search_videos.

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