select_payment_method

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

The description adds value beyond annotations by disclosing that only the upstream method ID is stored, never card numbers or CVVs, and that new/unlinked cards cannot be remembered until after the official payment flow. Annotations indicate mutability (destructiveHint=true) and idempotency, which align. No contradictions.

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, front-loaded with the main purpose, followed by a key limitation. Every sentence adds valuable information without redundancy. It is appropriately sized for the tool's complexity.

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 simple tool (2 parameters, 1 required) with annotations providing safety context, the description covers the essential behavioral details (security of remembering, limitation for new cards). It does not explain the output schema, but that is available separately, so the description is reasonably complete for guiding invocation.

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 must compensate. It mentions the core action (choose a payment method) and the optional remember feature, but doesn't explicitly explain that 'payment_method_id' is an integer ID from a list, nor does it detail the 'remember_for_future_orders' boolean's meaning beyond 'optionally remember its linked id'. The description adds some context but could be more precise about parameter roles.

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 verb 'choose' and the resource 'listed payment method', and distinguishes it from siblings like 'list_payment_methods' (which only lists) and 'clear_preferred_payment_method' (which clears). The purpose is specific and unambiguous.

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 this tool is for selecting a payment method from a list and optionally remembering it. It provides context about when remembering works (only for linked methods after official flow), but lacks explicit guidance on when to use this versus alternatives or when not to use it. It's clear enough for most cases.

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