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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so safety is covered. The description adds genuinely useful traits beyond that: per-row billing with `limit` capping both rows and cost, and an untrusted-input warning for user-generated content.

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, all front-loaded: purpose and ordering first, then alternatives, then return shape and billing. Every sentence earns its place with no filler.

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 (pk, caption_text, counts, taken_at). Billing model, cost implication, and untrusted-input handling round out what an agent needs 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 baseline is 3 and the schema documents `limit` and `user_id`. The description adds value by tying `limit` to cost ('caps both rows and cost') and by enumerating the returned row fields, giving meaning beyond the type constraints.

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 a TikTok user's videos'), the data source, and the ordering ('newest first'). It explicitly distinguishes itself from get_tt_media_by_id and get_top_tt_medias, so an agent can separate it from siblings without opening schemas.

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?

Gives a clear use case ('review an account's content') and names the two alternative tools with the conditions that select them (single-video detail vs platform-wide rankings). Nothing is left to inference.

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