check_payment_replay

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

Discloses that it records a fingerprint (side effect), requires environment variables for cross-process operation, and describes the return format. No annotations are present, but the description fully covers safety and behavioral traits.

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?

Concise, well-structured with a title statement, warning, and list of args and returns. Every sentence adds value with no 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?

Covers side effects, prerequisites (env vars), usage order, and return values. For a tool with 5 required params and no annotations, the description is fully complete.

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?

With 0% schema description coverage, the description provides brief but meaningful explanations for all 5 parameters (e.g., 'Amount as string (preserves precision)'), adding clarity beyond the schema's bare names and types.

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 tool checks for replay of a payment using a fingerprint. The verb 'check' and resource 'payment replay' are specific. However, it does not explicitly differentiate from siblings like screen_payment_metadata or check_payment_policy, though the distinct behavior is implied.

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?

Provides explicit guidance: 'Call exactly once, immediately before submitting the payment.' Also explains cross-process detection dependencies, helping the agent understand when and how to use the tool.

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