execute_payment

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

With no annotations, the description carries full responsibility and excels: it reveals that the PAN is never seen, that it waits for real confirmation, defines each status outcome and token lifecycle (burned on confirmed, kept for declined), and describes the overcharge/underspend protection. This is a model of transparency.

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 dense but every sentence adds useful information about behavior, statuses, or safety thresholds. It front-loads the purpose and uses compact listing of statuses, achieving a high information-to-word ratio.

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?

Without an output schema or annotations, the description compensates by fully enumerating return statuses and their implications for token handling. It also covers both happy path and failure modes (declined, unconfirmed, not_submitted, no_fields) and provides guidance on the actual_amount parameter, making it sufficiently complete for a complex payment execution tool.

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?

The schema already describes all 4 parameters with 100% coverage, so the baseline is 3. The description adds value by explaining why actual_amount is strongly recommended (overcharge block, underspend refund) and tying the submit_selector hint to the 'not_submitted' status, which enriches parameter semantics.

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 clearly identifies the action ('Execute a payment') and the resource ('a one-time token'), and adds specific behavioral detail (headless browser, card injection, confirmation watch). However, it doesn't explicitly differentiate from the sibling tool auto_pay_checkout, so it falls short of the highest score for sibling distinction.

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 provides strong usage context: it instructs to ALWAYS pass actual_amount for overcharge/refund protection, warns against blind retries on 'unconfirmed', and suggests supplying a submit_selector hint when 'not_submitted'. It does not name alternative tools or explicitly state when not to use this tool, so a score of 4.

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