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

Annotations already cover the read-only and open-world profile; the description adds real context beyond that by disclosing the returned fields (like counts, reply counts, pinned status, creator flag) and a 1-credit cost. It does not describe pagination depth or rate limits, but the cost disclosure is a meaningful addition the annotations cannot convey.

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 short sentences, front-loaded with the core action and scope, then the returned fields, then the routing hint and cost. Every sentence carries new information with no 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?

With no output schema, the description usefully enumerates what a comment record contains and flags the credit cost, which is what an agent needs before calling. The only gap is the undocumented cache_max_age parameter and any hint about pagination limits.

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 75%, so url, count and cursor are already documented; the description adds no parameter-level detail such as accepted URL formats or pagination semantics. The one undocumented parameter (cache_max_age) is left unexplained in both schema and description, keeping this at the baseline.

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 (comments on a video) and narrows the scope precisely to top-level comments, listing the fields returned. It explicitly distinguishes itself from the sibling tiktok_commentReplies, so an agent can select between them without opening either schema.

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?

Names the alternative tool (`tiktok.commentReplies`) and the condition that selects it — expanding a thread. It gives a clear context for use on a video's comments, though it does not state explicit exclusions beyond the reply-thread case.

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