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

The annotations declare idempotentHint=true, but the description describes a replacement operation whose 'answer carries the new secret exactly once,' implying each call generates a new secret and invalidates the previous one. This contradicts the idempotent hint and could mislead an agent about safe retry behavior.

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?

Three sentences, front-loaded with the action, followed by the immediate consequence and the critical response behavior. Every sentence earns its place 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?

The description covers the core operation, the destructive impact on existing deliveries, and the one-time return of the secret. However, it does not clarify retry or idempotency behavior, which is especially problematic given the conflicting annotation.

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% and the single parameter endpoint_key is fully documented in the schema. The description adds no additional meaning or format details for the parameter, so the baseline of 3 applies.

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 states a specific verb and resource: 'Replace a webhook endpoint's signing secret.' This is unambiguous and clearly distinguishable from siblings like save_webhook_endpoint or test_webhook_endpoint. No other sibling tool performs secret rotation.

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 clear context for when to use the tool: when you need to replace a signing secret and can relay the new one to the receiver. It does not name alternatives or explicit exclusions, but the operational consequences make the intended usage evident.

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