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

Annotations provide readOnlyHint:false and destructiveHint:false, so the description need not repeat safety basics. It adds valuable behavior: queue draining semantics ('Drain the queue'), the x402 payment requirement with status 402 and accepts[], and the projection constraint ('never wider' than granted scope). These are meaningful beyond annotations.

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: the first gives the action, the second adds the payment requirement, the third adds scope projection. Each sentence earns its place, and the most important information is front-loaded. Slight room for improvement would be explicitly tying the second sentence to the payment/mandate/credential parameters, but it is compact and purposeful.

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 pull operation with four parameters and no output schema, the description covers the key behavior: what is drained, who can use it, when payment is required, and how scope is bounded. It does not describe the return format or the exact mechanics of supplying payment, but that may be covered by the payment/credential parameter descriptions and the queue-draining framing is sufficient.

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 75%, so the schema already documents mandate, payment, and credential. The description adds context for payment (metered buyers receive status 402 until payment supplied) and buyer_key is required. The credential parameter's base64url format is in the schema. The description does not need to restate all parameter details; 3 is the baseline given high schema 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?

The description opens with a specific verb and resource: 'Drain the queue of pool records routed to you.' It clearly identifies the tool as a pull/consume operation for routed records, distinct from siblings like check_eligibility or get_quotes. The title 'Pull routed records (buyers)' reinforces the action and audience.

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 description states the tool is for pulling records routed to the caller as a buyer, and it mentions the x402 payment condition for metered buyers, which implies when payment parameters are needed. It does not explicitly name sibling alternatives or state when not to use this tool, but the context is clear enough for an agent to select it over the listed siblings.

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