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

Annotations declare readOnlyHint=false, and the description supplies the reason a lookup is not free of side effects: "1 credit when at least one account is found; free otherwise." That cost model plus conditional billing is real behavioral context an agent cannot get from the schema, though rate limits and failure/miss behavior are not discussed.

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 carrying distinct information: what it does, what it returns, what it costs. The core action is front-loaded and nothing is repeated from the schema verbatim.

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 correctly compensates by enumerating the return payload (creator, accounts with verdict, net confidence 0-1, evidence, websites). Cost and input constraints are covered; only edge-case behavior on a total miss is left implicit, despite the billing rule hinging on it.

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 both the url and platforms parameters are already documented, including the enum list and the "leave out for all" default. The description adds only the loose phrase "the other platforms," which does not clarify how platforms interacts with the input URL's own platform. 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 ("Find a creator's accounts") plus the exact input form (one Instagram, TikTok, YouTube or X profile URL) and the target platforms. It is clearly distinguishable from the sibling batch tools, which operate on sets rather than a single URL.

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 "from one ... profile URL" implicitly frames this as the single-lookup path versus start_batch/get_batch, and the schema adds the explicit exclusion of posts, reels, shorts and videos. It stops short of naming the batch siblings as the alternative for multiple creators, so the routing guidance is clear but not fully explicit.

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