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

Annotations only provide readOnlyHint=false, so the description carries the burden of explaining mutation. It clearly discloses destructive behavior ('Drain the queue'), the 402/payment flow for metered buyers, and the scope-projection guarantee ('never wider'). This is valuable behavioral context beyond the 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 with no filler. The primary action is front-loaded in the first sentence, followed by prerequisites and behavioral details. Every sentence earns its place.

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 simple queue-drain operation with a 4-param schema, no output schema, and minimal annotations, the description covers the action, prerequisites, payment state, and authorization scope. It does not describe the response shape or empty-queue behavior, but those are secondary for this operation.

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 buyer_key (required) and explains when payment is needed (status 402 with accepts[]), but it does not add meaning for mandate or credential. It partially compensates for the undocumented buyer_key but does not fully expand on all parameters.

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 uses a specific verb ('Drain') and resource ('queue of pool records routed to you'), and the title's '(buyers)' scoping makes the intended audience clear. However, it does not explicitly name sibling tools or contrast itself, so differentiation relies on the domain rather than explicit comparison.

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 implies when to use this tool: when you are a buyer with a queue of routed records and need to drain it. It also states prerequisites (buyer key) and a payment condition for metered buyers, but it does not provide when-not-to-use guidance or reference alternatives like get_quotes or register_agency.

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