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

Annotations already cover the read-only/idempotent/non-destructive profile, so the bar is lower; the description still adds real value by enumerating returned fields (url, name, eventTypes, scope, active) and warning that the HMAC secret is excluded and only exists at creation time. The required auth scope is also disclosed. No pagination or error behavior, but none is material for a single-resource fetch.

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 short sentences, front-loaded with purpose, then return shape, then the one caveat an agent must know. Zero 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?

No output schema exists, and the description compensates by listing the returned field set and the notable omission (secret). Combined with the explicit auth scope, an agent has enough to call it and interpret the result; only identifier-format ambiguity remains.

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 all three parameters including the account/workspace resolution rules are documented structurally. The description adds nothing about the identifier format (id vs name) or about the account/workspace overrides, so 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 and resource with an explicit scope: 'Fetch a single webhook by identifier.' The word 'single' plus the identifier requirement distinguishes it from pm_list_webhooks and pm_list_webhook_deliveries without the agent needing to open a 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?

Usage is implied by the required identifier, and the API-key scope `webhooks:read` is a useful precondition. However, it never names an alternative (pm_list_webhooks, pm_get_webhook_usage, pm_update_webhook) or states when not to call it, so routing is left to inference.

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