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

Annotations already declare readOnlyHint=true and openWorldHint=true, and an output schema exists, so the safety profile and return shape are covered elsewhere. The description's added detail (pagination support, returned fields) largely duplicates the schema's page_token description and the output schema, leaving modest incremental value.

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 dense sentence with the core purpose front-loaded and the disambiguation clause trailing. It is efficient, though listing return fields that the output schema already covers is slightly redundant padding.

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?

With annotations carrying the safety profile, a full output schema, and 100% parameter coverage, the description supplies the one thing structured fields cannot: the sibling-routing rule for keyword vs. ID/URL lookup. Nothing essential is missing 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 description coverage is 100%: keyword and page_token are both fully documented in the schema, including the warning not to pass content/profile links and the rule to preserve keyword across pages. The description adds nothing parameter-specific beyond that, so the baseline 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?

States a specific verb and resource (按关键词查找今日头条用户) and enumerates the returned fields (ID, name, bio, follower count, verification). The second clause distinguishes it from the by-ID/by-URL lookup siblings, so an agent can route correctly without opening another schema.

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 a clear when-to-use condition (search by keyword) and a when-not condition (if you already have a user ID or profile URL, query the profile directly). The alternatives are described by capability rather than named, so the agent must map them to toutiao_get_user_info_by_user_id / toutiao_get_user_info_by_profile_url itself.

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