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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds value beyond them by warning that full result documents can be large and by instructing the agent to preserve the cursor, has_more, and retrieval time for pagination, which is genuine behavioral context.

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?

Two front-loaded sentences with no filler; the search purpose comes first and the operational guidance second. The trailing list of three fields is slightly dense but still 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?

With an output schema present, return values need not be explained, and annotations cover the safety profile. The description supplies the size and pagination caveats an agent needs, though it omits any routing guidance among the many TikTok search siblings.

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%, so the schema already documents keyword, count (max 20), and offset. The description reinforces the count-size caution but adds little syntax beyond the schema, and its mention of "cursor" maps loosely to the offset parameter. 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 and resource ("Search TikTok mobile videos by keyword") and identifies the domain via the "mobile" qualifier. It does not, however, differentiate from the sibling tiktok_search or tiktok_search_hashtag, leaving the agent to infer which search variant to pick.

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?

It offers a practical operating tip ("keep count small") and says to preserve pagination fields, which is implied usage guidance. But it never states when to choose this tool over tiktok_search, tiktok_mobile_feed, or the other search siblings, and gives no exclusions.

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