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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=true, openWorldHint=true), and the description adds substantial context beyond them: the underlying PATCH endpoint, partial-update semantics ('Only the fields you pass change'), the returned payload, and specific failure modes (not_found, validation_error). One mild tension: the 'pause...without losing the registration / use delete_webhook to stop for good' framing reads as reversible, which sits awkwardly beside destructiveHint=true, though overwriting a secret or event list can reasonably be called destructive.

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 action and fields, then endpoint, then usage routing, then return/error behavior — a sensible order with no filler sentences. It is slightly longer than strictly necessary (the docs URL sentence and the return/error recap both repeat ground covered elsewhere), but every element is relevant.

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?

There is no output schema, so the description carries the burden and does so: it names the returned fields (id, url, events, is_enabled) and the two error cases. Combined with the partial-update rule and the sibling routing, an agent has everything needed to call this correctly.

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 and the schema already explains each field. The description goes further by supplying an event-name example, noting the short-secret validation, and stating the constraint 'Only the fields you pass change. Pass at least one' — a partial-update rule the schema's nullable/default-null properties do not convey.

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 ('Change a PinBridge webhook's URL, secret, events or enabled flag') and enumerates the mutable fields, so the agent immediately knows what the tool operates on. It also contrasts itself with the delete_webhook sibling, making it distinguishable without opening 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?

Gives explicit when-to-use guidance (pause deliveries via is_enabled=false, rotate secret without losing registration) and an explicit when-not-to/alternative ('to stop for good use delete_webhook'). It even states the precondition 'Pass at least one' field, which is exactly the invocation rule an agent needs.

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