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

Annotations already declare read-only and open-world, so the description's job is to add operational context, which it does: it discloses the result payload and the per-page billing rate ($0.006). It stops short of noting pagination behavior for the pages parameter or latency/rate limits, but the safety and cost profile is covered.

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?

Four tight sentences with no filler: purpose and return payload first, then filters/sorts, then the sibling routing, then cost. Every sentence carries an operational fact.

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 enumerating the returned fields, and for a six-parameter read-only search tool it covers purpose, capabilities, alternative tool, and price. Nothing an agent needs in order to call it correctly is missing.

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% and the enums spell out the meaning of publish_time and sort_by, so the schema carries nearly all parameter meaning. The description restates the filter/sort capabilities and adds pricing tied to the pages parameter, but contributes little interpretation beyond the schema, matching the baseline for fully documented schemas.

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 ('Search TikTok videos by keyword') and immediately enumerates what comes back: title, URL, engagement metrics, author metadata, music, publish date. An agent can distinguish it from search_tiktok_hashtags and search_tiktok_users without opening a 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?

Explicitly routes the single-video case to tiktok_video_details and names the available filters/sorts for this tool. It does not, however, contrast itself with the other TikTok search siblings (hashtags, users) or with tiktok_hashtag_videos/tiktok_user_videos, leaving some selection ambiguity.

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