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

Annotations already declare readOnlyHint and openWorldHint, but the description adds genuinely non-obvious behavioral context: page_token pagination is supported, results across pages may contain duplicates, and termination is signalled by an empty next_page_token. The listed return fields are partly redundant given an output schema exists, which keeps this just short of a 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?

Three sentences, front-loaded with purpose, then alternative routing, then the pagination caveat. Every sentence carries distinct information and none is 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?

For a two-parameter read tool with full schema coverage, an output schema, and annotations covering the safety profile, the description supplies the remaining decision-critical facts: sibling routing and the pagination duplication/termination semantics. Nothing needed to call it correctly is missing.

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 both parameters (keyword, page_token) are already documented in the schema, including the instruction to keep keyword unchanged across pages. The description's mention of page_token pagination behavior adds context but no syntax or format detail beyond the schema, 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?

The description states a specific verb and resource (按关键词搜索微博用户) and enumerates the returned fields, so the agent knows exactly what this tool produces. It is clearly distinguishable from siblings like weibo_search_posts and weibo_get_user_info_by_user_id, both of which it names.

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 explicitly routes the agent: use post search for posts (查找帖子使用帖子搜索), and use the user-detail tool when a user_id or profile URL is already known. Both alternatives and the conditions that select them are stated, leaving nothing to inference.

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