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

Annotations declare readOnlyHint=true and openWorldHint=true, establishing this as a read-only network access tool. The description adds value by mentioning it returns both article details AND body content ('正文'), which explains the output scope. However, it doesn't disclose edge cases like what happens with invalid or expired links. No contradiction with annotations.

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, efficient sentence that fits within the established field limit. The parameter description is well-structured with delimiters (；-separated: one part in the schema type and another in the example), length indicators, and example separators. It's concise and functional, though the embedded format markers add minor noise.

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 single-parameter tool with 100% schema coverage, an output schema present, and clear readOnly annotations, the description is adequately complete. It functions well alongside its siblings, though it could have mentioned what fields appear in the returned article details or specified any expected error behavior for expired links.

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 the schema fully documents the url parameter—the description repeats this same information with an example URL. The description adds marginal context by clarifying accepted input forms (link or share text), though this was already explicit in the schema's type description. This aligns with the baseline of 3 when schema has full coverage.

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 tool's function: '获取微信公众号文章详情和正文' (get WeChat article details and body content). It uses a specific verb+resource structure and distinguishes itself from sibling tools that handle videos (wechat_get_video_detail_by_url), users (wechat_get_user_info_by_url), and comments (wechat_get_video_comments_by_url) by focusing specifically on MP articles.

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 indicates the accepted input format (URL or share text containing the URL). While it doesn't explicitly name alternatives, the sibling context provides clear differentiation—for video URLs, wechat_get_video_detail_by_url would be used instead. The tool's scope is well-defined and self-contained for article fetching.

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