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

Annotations already flag destructiveHint=true and idempotentHint=true, so the description's added value is the state-reset disclosure ('clears its failure count') and the credential requirement ('Needs a key') — both genuinely beyond the annotations. It stops short of explaining what 'destructive' means here (e.g. that enabled=false pauses all deliveries), which would have made it a 5.

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?

One front-loaded sentence names the resource, enumerates the mutable fields, and appends the prerequisite. No filler and no repetition of the tool name.

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 5-param mutation tool with full schema coverage and annotations, the description covers purpose, fields, auth, and the enabled-reset behavior. The main remaining gap is that the destructive nature of disabling (pause of live deliveries) is never stated in prose, even though the annotation hints at it.

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 schema already spells out each param, including that enabled true clears failures. The description only restates those same fields, adding no syntax, format, or inter-parameter semantics for 'id' or 'events' patterns. Baseline 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?

States a specific verb ('Change') and resource ('an account webhook') plus the exact mutable fields, which clearly separates it from sibling create_webhook, delete_webhook, and rotate_webhook_secret. An agent can identify the operation without opening the 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?

'Needs a key' conveys the prerequisite, and the mention of 'enabled (true turns it back on)' implies the re-enable use case. However, there is no explicit guidance on when to prefer this over create_webhook/delete_webhook or on what happens if a webhook is disabled and other fields are changed.

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