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

Annotations only declare the safety profile (not read-only, not idempotent, not destructive). The description adds genuine behavior the annotations cannot convey: lease-based claiming, at-least-once delivery, expiry-driven redelivery, and the resulting idempotency requirement on the caller's work.

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, front-loaded with the core action, then the follow-up protocol, then the failure semantics. No filler; every clause conveys actionable information.

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 tool with no output schema and a fully documented input schema, the description covers the operational contract an agent needs (claim, ack/nack, lease expiry, idempotency). It does not hint at what a claimed message payload contains, which is the only minor gap.

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 parameter meaning is fully carried by the schema. The description reinforces 'max' and the lease concept but adds no syntax or format detail beyond what the schema already documents. 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 (claim) plus resource (messages from a queue) and scope (up to max), and situates it among siblings by naming queue_ack and queue_nack. An agent can distinguish it from queue_put/queue_status/queue_extend without opening any schema.

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?

Gives clear workflow context: claim, then finish with queue_ack or queue_nack to retry later, and warns that an expired lease hands the message onward. It names the alternative follow-up tools, but does not state when not to use this tool (e.g., vs. queue_status or queue_dead).

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