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

With no annotations, the description carries the full burden and does it well: it discloses the hard 100-id cap, that the server SILENTLY drops extras, that missing ids produce no error row, that row order is not guaranteed, and that returned content is untrusted user-generated input. These are exactly the operational quirks an agent would otherwise discover by failure.

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?

Five tight sentences, zero filler, front-loaded with the capability and cap before the edge-case behaviors. Every sentence carries a distinct 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?

There is no output schema, and the description compensates by enumerating the returned fields, explaining how absent ids appear, and warning about ordering and untrusted content. Nothing an agent needs to call this correctly or interpret results 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 schema already documents both params including the string-vs-int pk rationale and the server-side drop behavior. The description largely restates the cap rather than adding new meaning, so the 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 (get), resource (TikTok user profiles), key (pk), and batching mode (by ids, single call) — enough to distinguish it from the sibling get_tt_user_by_id (single) and get_users_by_ids (non-TikTok). It also names the exact projection returned, so the agent knows the shape of what it gets before 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?

The phrase 'up to 100 ... in a single call' clearly frames the batch use case, so an agent can tell this is the multi-id variant rather than the single-lookup tool. It stops short of explicitly naming the alternative or stating a when-not-to-use condition (e.g., for one pk prefer get_tt_user_by_id), so it lands at clear-context rather than explicit routing.

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