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

Annotations declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=true, so the agent knows this is a non-idempotent write with external effects. The description adds the notification scope (verification lifecycle), which is useful context, but does not disclose whether the endpoint must be verified, whether creation fails on duplicate URLs, or anything about the returned webhook identifier. For a mutation tool, more behavioral detail would help.

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?

A single front-loaded sentence with a clear verb-resource-entity structure. Nothing is wasted and the core purpose is stated first.

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 2-parameter creation tool with full schema coverage and annotations covering the safety profile, the description covers the essential purpose but stops short of explaining what happens on creation (e.g., returned webhook ID, activation requirements) and doesn't note the absence of idempotency in a way an agent would act on. Adequate but with clear gaps.

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 both url and events are fully documented in the schema, including the HTTPS requirement and the event enum values. The description adds no parameter-level detail beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 'Create' and resource 'webhook endpoint', and scopes its purpose to 'verification lifecycle notifications', which distinguishes it from siblings like list_webhooks and delete_webhook. An agent can immediately tell this is the creation counterpart to those tools.

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 usage (create a webhook to receive verification lifecycle notifications) but gives no explicit when-to-use versus alternatives, no mention of list_webhooks for inspection, and no prerequisites like required permissions or whether duplicate URLs are allowed. Sibling tool delete_webhook makes the create/delete pairing inferable, but no explicit routing guidance is provided.

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