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

The annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the mutation profile is known from structured data. The description adds real value by saying the new secret is returned and implying immediate downstream breakage via the 'update verification logic' warning. However, it never confirms that the old secret becomes invalid instantly, whether a grace period exists, or whether rotation is reversible — key facts for a destructive, non-idempotent call.

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 short sentences, none redundant, with the core action and the returned value front-loaded and the operational warning placed last where it reads as a consequence.

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?

It's a destructive, single-parameter mutation with no output schema, and the description covers the return value and the operational follow-up, which is the essential context. It stops short of explaining old-secret invalidation timing and irreversibility, which an agent handling a destructive call would benefit from.

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?

Only one parameter (webhookId) with 100% schema description coverage, so the schema already does the work. The description adds nothing about the identifier format, and per the baseline for high coverage a 3 is appropriate.

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?

States a specific verb and resource: "Rotate the HMAC signing secret for a webhook." It also declares the return value ("Returns the new secret"), which is more than most sibling webhook tools offer. It does not explicitly name how it differs from register_webhook or delete_webhook, but the verb is distinct enough to separate it in practice.

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 phrase "Update your webhook verification logic immediately after rotating" tells the agent what to do afterwards, but never states when rotation is appropriate or what alternative exists. Usage is only implied by the tool name; there are no exclusions or prerequisites such as permissions or risk conditions.

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