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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral details: each item includes a status field with enumerated values (pending, approved, settled, declined, expired), and pending requests include an approval_url to re-surface to the user. This adds context beyond the annotations without contradicting them.

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 description is well-structured and front-loaded with purpose, then usage guidance, then parameter docs. Every sentence earns its place; there is no filler. The parameter explanations are compact and precise.

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 list tool with two optional parameters and no output schema, the description provides sufficient information: the purpose, what each response contains (status, approval_url), and the routing to get_payment_result. It doesn't detail the exact response shape, but the described fields are enough for an agent to interpret results. Minor gap: no mention of pagination beyond 'newest first' and a cap, which is acceptable for this scale.

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 0%, so the description carries the full burden for parameter meaning. It thoroughly explains both parameters: status ('open' default vs 'all') and limit (default 20, capped at 100, newest first). This fully compensates for the schema's bare type/default definitions.

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: 'List this agent's payment requests and whether each has been approved yet.' This clearly distinguishes it from siblings like get_payment_result (single charge) and request_payment (creation). The agent can immediately tell what this tool does without ambiguity.

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?

Explicit guidance is given: 'Use this to see the state of every request you've made — not just poll one saved charge_id.' It also directs the agent to a sibling tool for post-approval: 'once a request is approved, call get_payment_result(charge_id) to fetch the card.' This fully covers when to use this tool versus alternatives.

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