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

Annotations already cover read-only, open-world and non-destructive safety, so the bar is lower. The description adds real behavioral context beyond them: per-page billing ($0.006), a surcharge for get_sentiment, and the full shape of returned data. It doesn't discuss rate limits or result caps, keeping it just under 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 dense sentences with no filler: purpose and returns first, then the sibling routing, then cost. Every clause carries information an agent needs.

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 present, the description compensates by enumerating return fields (title, URL, metrics, author, music, publish date) and disclosing cost. For a 6-parameter search tool this covers everything needed to call it correctly.

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 schema already documents every parameter including enum values and defaults. The description restates the sort options and filters but adds no syntax or format detail beyond what the schema provides, so baseline 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+resource ('Search TikTok videos by keyword') and enumerates the returned fields, so the agent knows exactly what comes back. It explicitly distinguishes itself from tiktok_video_details, which is the nearest sibling.

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 ('Use tiktok_video_details for one video's full details'), giving a clear routing condition for the search-vs-detail split. It stops short of stating when NOT to search (e.g., single known URL), so it is not fully exhaustive.

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