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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, covering the safety profile, so the description's burden is lighter. It adds a genuinely useful behavioral detail beyond annotations: an empty user_list signals no exact match. It could say more about response shape, but with rich annotations a small gap is acceptable.

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 sentences, each earning its place: the resolution purpose, the workflow entry-point role, and the no-match failure semantics. Purpose is front-loaded and there is zero 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?

For a 2-parameter resolver with full schema coverage and strong annotations, the description covers the essential operational context: what it returns, how it feeds the creator family, and what an empty result means. The only notable absence is a fuller compact-response shape, but the expand parameter and workflow note cover most agent needs.

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 fully documents handle and expand (including the 500 KB warning and leading-@ behavior). The description's mention of sec_uid output mildly reinforces handle's purpose, but it adds no new parameter-level meaning beyond the schema — baseline 3 is correct.

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?

The first sentence names a specific verb (resolve), resource (@handle), and concrete outputs (numeric uid and sec_uid). The 'Start here' sentence anchors its role relative to the tiktok_creator_* sibling family, and the mention of 'handle' clearly separates it from the other resolve-style siblings (hashtag, sound).

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?

'Start here: every tiktok_creator_* tool takes the sec_uid this returns' is explicit when-to-use guidance that names the downstream consumers. The empty user_list note adds result-interpretation guidance. It stops short of explicit when-not-to-use phrasing, but the sibling naming makes the routing clear.

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