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

Annotations already provide readOnlyHint=true and openWorldHint=true, establishing safe read-only behavior and external dependencies. The description adds the constraint '不要传回复项的 comment_id' and the ID-completion workflow, but these are more about parameter semantics and usage rules than new behavioral context (e.g., rate limits, side effects). Thus, it adds minimal extra beyond annotations, warranting a 3.

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, tightly-packed sentence (in Chinese) that front-loads the core purpose and then provides actionable rules. Every clause adds value, with no fluff or repetition. It is efficient and well-structured for an agent to parse quickly.

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?

Given the tool has an output schema, detailed parameter schema, and annotations (readOnly/openWorld), the description sufficiently covers the essential ID resolution workflow and cardinal rule about comment_id. It does not explicitly mention pagination behavior, but that is thoroughly documented in the schema for page_token. The only minor omission is lack of mention of error handling or invalid-ID scenarios, but those are often left to the system. Overall, it is complete for effective use.

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%, with detailed descriptions for all three parameters: photo_id derivation, comment_id (including the note about not using reply ids), and page_token (opaque, must reuse exactly). The description itself does not add new semantic detail beyond what the schema already states, only restating the comment_id constraint, so it earns the baseline score of 3.

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 fetches comment replies given a photo_id and a first-level comment_id, and explicitly instructs not to pass reply-level comment_ids. This distinguishes it from sibling tools that retrieve first-level comments (kuaishou_get_video_comments_by_photo_id/by_url) and other video-focused tools, leaving no ambiguity about its specific function.

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 explicit when-to-use instructions: use directly when a complete valid ID pair is provided, call the appropriate first-level comment tool when IDs are missing, request work location info from the user when needed, and never pass a reply comment_id. It names the alternative tools implicitly ('一级评论工具') and provides clear decision logic, which is more than typical guidance.

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