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

Annotations already declare destructiveHint=true and openWorldHint=true, and the description adds genuinely new context: only supplied fields change, events are replaced wholesale, headers cannot be set here, existing headers are preserved and returned as [hidden]. That explains the blast radius of the destructive mutation and the credential-handling constraint, well beyond what annotations convey.

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?

Single dense paragraph with the purpose front-loaded and every clause carrying information (partial-update semantics, wholesale event replacement, header restriction, id lookup). It is longer than average but not padded; a light structural break would help readability without losing content.

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?

An output schema exists so return values need not be spelled out, and the description still flags the relevant response element (dashboardUrl). For a destructive, open-world mutation with five parameters, the description covers scope, side effects, and the credential pitfall, leaving nothing an agent needs to call it safely.

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 description coverage is 100%, so the baseline is 3, but the description adds semantics the schema does not: events are replaced wholesale rather than merged, and status inactive pauses deliveries while active resumes them. This meaningfully clarifies update behavior of two parameters.

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 opens with a specific verb and resource plus the exact updatable fields ("Update a webhook's name, https URL, subscribed events or status"), and it names list_webhooks as the way to obtain the id. An agent can distinguish this from create_webhook, delete_webhook and get_webhook 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?

It states the mutating nature, directs the agent to list_webhooks for the id, and gives a strong negative instruction: never ask the user for header values and instead hand back the response's dashboardUrl. It stops short of an explicit when-not-to-use rule or a named alternative for header editing beyond the dashboard pointer.

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