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

Beyond the annotations, it discloses that Last Price sends a signed POST for each listed event, that the response contains a whsec_ signing secret, and that unknown event names are refused. It also states the owner/admin role requirement, the key-scope/sign-in constraint, and the 403 refusal for sandbox keys until the workspace is claimed.

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?

The description is front-loaded with the core operation and then adds only consequential details: signing secret, event validation, ping follow-up, and access constraints. Every sentence carries information needed to call the tool correctly, with no 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?

Given the moderate schema, absent output schema, and non-destructive create annotations, the description is complete enough for correct invocation. It covers authentication prerequisites, workspace state, event-name validation, the returned signing secret, and the recommended verification step.

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 coverage is already 100%, so the schema documents the three parameters. The description nonetheless adds useful meaning about the events field: it names event categories, says the documentation lists names, and states that unknown names are refused. It also clarifies that the returned signing secret is used to verify deliveries.

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 first sentence gives a specific verb and resource: 'Add an outbound webhook endpoint,' then explains the signed POST behavior to the https URL. It also distinguishes this from ping_webhook by explicitly telling the agent to use ping_webhook afterward to verify the endpoint.

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 gives clear operational context, including prerequisite roles, key scope limits, and the claimed-workspace requirement. It also routes the agent to ping_webhook as the follow-up check, though it does not explicitly mention update_webhook or list_webhooks as alternatives.

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