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

Annotations only declare write, non-idempotent, non-destructive, closed-world; the description adds real substance with the 30-900s range, the 60s default, the cap at the original queue expiry, conflict semantics for stale receipts, and the explicit guarantee that queue lifetime is not extended. The main remaining gap is whether a successful renewal rotates or preserves the receipt, which matters given idempotentHint=false.

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?

Four short sentences, front-loaded with the action, then the constraint, then the failure mode, then the invariant. No filler and nothing buried.

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 non-idempotent mutation with full schema coverage, annotations, and an output schema, the description covers limits, defaults, failure, and invariants well. The one unresolved point an agent would want is post-renewal receipt validity, which the output schema may cover but the description leaves unstated.

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 coverage is 100%, so every parameter is already documented, including the visibility_timeout bounds and default. The description largely restates the visibility constraints and adds only light framing around the worker token and receipt being the credentials for the call.

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: move the active claim deadline, using the worker token and current receipt. This clearly separates it from acquire/claim (initial claim), release_agent_queue_job (give up), and renew_lease (a different lease subsystem).

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?

Implies the correct usage context (you hold an active claim with a receipt) and states the failure condition: a stale or expired receipt is a conflict. It does not explicitly name the alternative tools for other lifecycle stages, so an agent must infer that claim/release are the siblings for those cases.

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