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

The description adds valuable behavioral context beyond annotations: revalidates the quote and default method, checks the original signup, sends at most one confirmation request, and never retries an ambiguous charge. This complements the destructiveHint annotation by detailing the safety measures taken.

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 two sentences long, with the core action and condition in the first sentence, and supplementary behavioral details in the second. Every sentence adds value without redundancy.

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 moderate complexity, no output schema, and 0% parameter coverage, the description covers the tool's purpose and behavior well but lacks explanation of the confirmationToken parameter and the return value/outcome of the tool. This is a minor gap.

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 has 2 parameters (confirmed, confirmationToken) with 0% description coverage. The description provides minimal explanation: it mentions 'pending saved-method plan payment' and 'displayed prepared quote' but does not explicitly map to the parameters or explain their specific roles. The confirmed parameter's const:true is not mentioned.

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 states the action ('Confirm the pending saved-method plan payment'), the resource ('pending saved-method plan payment'), and the condition ('only after the user explicitly approved the displayed prepared quote'). It distinguishes itself from sibling tools like prepare_plan_payment by specifying the prerequisite.

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 gives explicit guidance on when to use the tool: only after user approval of the prepared quote. It also describes internal steps (revalidates, checks, sends at most one, never retries), implying when not to use (e.g., if charge is ambiguous). However, it does not explicitly list alternatives or when not to use beyond the precondition.

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