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

The annotation readOnlyHint already declares safe read behavior, but the description adds valuable context: 'Secrets are never returned by this tool.' This discloses a security-relevant trait that is not in the annotations or schema, helping agents avoid expecting secret values. No contradiction with annotations.

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?

Two sentences, front-loaded with action ('List all webhook endpoints'), followed by a crucial caveat about secrets. Every word earns its place, with no filler or repetition of schema data.

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 simple list operation with no parameters and no output schema, the description covers the purpose and a key behavioral note. It could mention pagination or response format, but the absence of an output schema and presence of readOnlyHint reduce the need. Given the low complexity, the description is sufficiently complete.

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?

The tool has zero parameters, and the schema coverage is 100% (empty properties). Per the baseline for no-parameter tools, the description does not need to add parameter details. The score reflects that the description adequately addresses the parameter space by not pretending otherwise.

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 clearly states the tool lists all webhook endpoints for the authenticated account. The verb 'List' and resource 'webhook endpoints' make the purpose explicit, and it distinguishes from sibling tools like register_webhook and delete_webhook which perform different actions.

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 implies use for viewing registered webhooks but does not explicitly state when to prefer this over alternatives. With many webhook-related siblings, providing a direct contrast (e.g., 'to view a single webhook, use get_webhook') would strengthen guidance.

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