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

Annotations are empty, so the description carries the full burden. It discloses the operation (list replies), required parameters, and pagination behavior. However, it does not explicitly state that the operation is read-only and non-destructive, though this is implicitly clear. No contradictions exist.

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 two sentences with no unnecessary words. It is front-loaded with the purpose, then adds usage context. Every word earns its place.

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?

The description covers the essential aspects: what it does, required parameters, and pagination. However, since there is no output schema, the description could have added more detail about the return structure (e.g., that it returns a list of replies with cursor fields). Still, for a simple list operation, it is adequate.

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 baseline is 3. The description adds context by restating that video_id and comment_id are required and explaining cursor usage. This provides marginal additional value beyond the schema.

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 'List replies to a specific comment on a video', using a specific verb and resource. It distinguishes from sibling tools like tiktok_video_comments (which lists top-level comments) by focusing on replies to a specific comment.

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 explicitly says 'Use to drill into a comment thread' and notes the required parameters (comment_id, video_id) and pagination with cursor. It provides clear context for when to use the tool, though it does not explicitly state when not to use it (e.g., for top-level comments), but the sibling tool tiktok_video_comments covers that case.

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