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

Annotations already declare the mutation/open-world/non-idempotent profile, so the safety story is covered. The description adds genuinely useful context the annotations cannot: asynchronous execution, the returned handle, and the per-row billing rule ("charged only if it finds accounts"). It says nothing about failure handling, per-row errors, or whether re-submitting the same URLs double-charges.

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 short sentences with zero filler: capability and limit first, the follow-up step second, cost model last. Every sentence carries information the agent needs before invoking.

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 two-parameter async submission tool with no output schema, the description covers what the agent needs: the input shape, that a batch id comes back, how to retrieve results, and the billing implication. Only the partial-failure and retry/idempotency story 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?

The schema already documents both parameters, including the restriction that URLs must be profile pages rather than posts or reels. The description's "up to 500" restates maxItems and mentions profile URLs without adding format or batching semantics, so it is roughly a baseline pass-through rather than compensating for the 50% coverage.

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 ("Queue ... profile URLs to look up in the background") plus the scale limit of 500, which distinguishes it from the single-record sibling lookup_creator and the polling sibling get_batch. An agent can tell immediately this is the bulk-submission entry point.

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?

Explicitly routes the agent forward: "poll it with get_batch" tells the agent this call only enqueues and does not return results. The bulk framing implicitly contrasts with lookup_creator, but it never says when NOT to batch (e.g. one or two URLs) or what happens on partial failure.

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