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

Annotations already declare readOnly/openWorld/non-destructive, but the description adds substantive context beyond them: default TikTok ordering, the returned fields (text, author profile, like/reply counts, date), page size of 50, and per-page billing cost. It does not cover auth needs or rate limits, so it stops short of a 5.

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 tight sentences, front-loaded with the verb and scope, then usage routing, then output/pagination/billing. Every sentence carries information an agent needs; nothing is 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 compensates by listing the returned fields, page size, and ordering. It covers input selection, output shape, sibling routing, and cost — complete for a paginated read tool.

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 url, video_id, pages, and get_sentiment are already fully documented in the schema. The description reinforces the mutual-exclusion rule ('provide exactly one') and page size, but adds little syntax or format detail beyond the schema; baseline 3 is appropriate.

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 ('Get the top-level comments on a TikTok video') and pins down the scope as top-level only. It explicitly contrasts with the sibling tiktok_comment_replies, so an agent can distinguish the two 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_comment_replies) and the condition that selects it ('for a comment's thread'). Combined with the 'top-level comments' scoping, the agent knows exactly when to use this versus the sibling.

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