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

Annotations flag destructiveHint/openWorldHint, but the description adds the context those hints cannot: update has outbound side effects, delete requires a two-step preview_id handshake, and test sends a signed delivery. It also discloses what the preview returns (URL, events, workspace) and that preview_id is required to confirm — value well beyond the annotation block.

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?

Front-loaded with the core purpose and the prerequisite call, then segmented by action label so an agent can scan to the relevant branch. It is dense and semicolon-heavy in a single block, which costs a little readability, but no sentence is filler.

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 9-parameter destructive multi-action tool with no output schema, the description covers every branch, the confirmation gate, the preview return fields, and the discovery prerequisite. An agent has everything needed to call each action correctly on the first attempt.

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%, so baseline is 3, but the description adds conditional semantics the schema cannot express: which parameters apply to which action, that confirm means different things for update/test vs delete, and the confirm + preview_id pairing. It stops short of explaining events payload shape or workspace_id null behavior beyond what the schema already states.

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+resource ('Change a webhook subscription') and then enumerates the three supported operations (update, delete, test) with their required identifier, each in a labeled clause. An agent can distinguish this from create_webhook and list_webhooks without opening any schema.

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 routes the agent through list_webhooks first to obtain the webhook_id, names the three actions and what each one does, and gives a clear when-to-confirm rule ('pass confirm=true only after explicit confirmation'). For delete it prescribes an exact preview-then-confirm sequence, leaving nothing to inference.

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