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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It adds useful context by stating that notifications are metadata-only and signals mutation via 'Register'. But it does not describe what happens upon registration, whether the secret is used for payload signing, or any delivery/failure behavior.

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 compact sentence with the action front-loaded and zero wasted words. Every element — HTTPS, the event type, and the metadata-only scope — earns its place.

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 two-parameter create tool, the description is close to adequate but still has gaps: the secret parameter is undocumented, and there is no mention of the registration response or the fact that the webhook becomes active. With no output schema or annotations, slightly more context would be needed for fully confident invocation.

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 0%, so the description must compensate for both parameters. It adds the HTTPS constraint for the url and the 'metadata only' qualifier, but leaves the secret parameter completely unexplained — its purpose, optionality, and format are all unknown to the agent.

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 uses a specific verb (Register) and resource (HTTPS webhook) and scopes it to the email.received event with a 'metadata only' qualifier. It clearly differentiates this tool from sibling tools like inbox_webhook_list, inbox_webhook_delete, and inbox_webhook_deliveries_list.

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 purpose is clear enough for an agent to recognize this as the creation tool versus the list/delete/deliveries siblings. However, it gives no explicit when-to-use or when-not-to-use guidance, nor does it name any alternative, so it falls short of a 5.

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