verify_signature

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

Discloses timing-safe comparison, requirement for webhook secret and paid plan, and that it returns authenticity status. Without annotations, the description provides adequate transparency about behavior and constraints.

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?

Two sentences, front-loaded with the main action, and no extraneous information. Every sentence adds value.

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?

For a simple two-parameter tool with no output schema, the description covers what, how (timing-safe), when (before acting), and prerequisites. Return format is implied, which is acceptable for a boolean-like check.

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 coverage is 100% with clear parameter descriptions for slug and requestId. The description reinforces their purpose but does not add significant new meaning beyond what the schema provides.

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?

Description clearly states the tool verifies HMAC signatures of callbacks, specifying supported integrations (Stripe, GitHub, Shopify) and the timing-safe comparison. It distinguishes from siblings like get_callback_payload or replay_callback by focusing on authentication verification.

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?

Explicitly advises using this before acting on a payload, and outlines prerequisites (webhook secret, paid plan). While it doesn't explicitly exclude scenarios or compare alternatives, the context is clear about when to invoke.

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