Capture payment

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

Annotations already include destructiveHint=true and idempotentHint=true, and the description reinforces this with 'MOVES REAL MONEY — irreversible.' This adds significant behavioral context about financial risk beyond the annotations, making the tool's impact unmistakable.

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 extremely concise: one line with three short statements. Every phrase adds value, from the core action to the partial-capture option to the financial warning, with no filler.

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?

Given the output schema exists and annotations cover safety profile, the description provides sufficient context: purpose, partial capture behavior, and irreversible financial impact. The prerequisite of a held payment is implied by 'capture held funds', making it complete for an agent to invoke correctly.

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%, with both payment_id and amount fully documented. The description's mention of 'Optionally capture a partial amount' merely restates the schema's 'Amount for a partial capture (optional...)', adding no new meaning beyond the structured definition.

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 explicitly states the verb 'Confirm' and specific resource 'two-step payment (capture held funds)', clearly distinguishing it from siblings like create_payment or cancel_payment. It also mentions optional partial capture, adding specificity.

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 clearly implies when to use this tool: when confirming a two-step payment and capturing held funds. It does not explicitly name alternatives or exclusion criteria, but the context is unambiguous enough for an agent to select it correctly.

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