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's pagination hint is a useful behavioral trait, but it largely duplicates what the page_token schema field already spells out in more detail (3-day token validity, same-article-only chain), so it adds little beyond structured fields.

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?

Two short clauses separated by a semicolon, with the core purpose front-loaded and no filler. Slight redundancy with the schema's page_token documentation keeps it from being maximally tight.

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 an output schema present, return values need not be described, and both parameters are fully documented in the schema. The description covers purpose and pagination adequately; only the relationship to the comment-replies sibling and result ordering/limits are unaddressed, which are minor gaps.

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 schema already explains that url accepts a link or share text and how page_token works, including the 3-day expiry. The description adds no syntax, format, or edge-case meaning beyond that, 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?

States a specific verb and resource: retrieve the comment list for a WeChat Official Account article, keyed by URL or share text containing the URL. This clearly separates it from video-comment siblings, though it never explicitly contrasts with wechat_get_mp_article_comment_replies_by_url (replies vs. top-level comments), leaving that distinction to the tool name.

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 second clause gives concrete pagination guidance ('reuse the returned next_page_token when continuing'), which is real usage instruction. However, there is no statement of when to choose this over the sibling replies tool or the URL-vs-object-id comment variants, so selection guidance is only implied.

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