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

Annotations only declare readOnlyHint=false, destructiveHint=true, and openWorldHint=true. The description adds materially useful context the annotations do not: the tool requires an x402 payment, the payment signature must go in _meta['x402/payment'], and pricing is $0.0001 per emitted URL — critical for an agent deciding whether to invoke a paid, charge-accruing operation.

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?

The opening sentence is generic actor-wrapper boilerplate ('calls the Actor ... and retrieves its output results') that restates the mechanism rather than adding information. The payment paragraph is dense and earns its place, but the framing sentence dilutes front-loading.

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 an output schema present, return values need no explanation, and the payment/auth requirements plus the actor's purpose are covered. What is missing is any note on error behavior or how to retrieve emitted URLs after a run, though the schema's waitSecs/nextStep text partly compensates.

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 all five parameters (including start_urls discovery semantics and waitSecs polling behavior) are already documented in the schema. The description adds no parameter-level meaning beyond that, which is the expected baseline when the schema carries the load.

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 description names a specific actor and its function ('Discover and expand sitemaps into crawl URLs'), which is a concrete verb+resource. It does not, however, differentiate itself from the sibling tools (get-actor-run, get-dataset-items), so an agent must infer the distinction from the actor name alone.

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?

It states a prerequisite (a valid x402 payment signature in _meta) but gives no guidance on when to choose this tool versus the sibling run/dataset tools, nor any exclusions or follow-up path beyond what the schema's waitSecs text already implies.

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