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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds no behavioral context beyond that — it doesn't mention that the endpoint is registered outside this system, any verification/handshake, auth scope, or rate limits.

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 zero filler. It is appropriately sized and wastes no words, though its brevity is part of why other dimensions are thin.

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 write tool with annotations covering the safety profile and a 100%-documented schema, the essentials are callable. However, nothing explains the superadmin-only customerId delegation, endpoint verification, or delivery behavior, leaving real gaps for a webhook-creation tool.

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 schema already documents url, events (with a full event list), customerId (superadmin-only), and description. The description adds no parameter meaning beyond the schema, making 3 the correct baseline.

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) plus its purpose ('for receiving event notifications'). An agent can tell it apart from delete_webhook/update_webhook/list_webhooks by the verb, though the description does not explicitly name those siblings.

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?

No guidance on when to create a webhook versus updating an existing one (update_webhook) or listing them (list_webhooks). The 'create' verb implies the intent, but nothing states prerequisites, alternatives, or when this is the right choice.

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