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

Annotations already mark idempotentHint=true, but the description adds material detail: same URL returns same id, secret generation behavior, secret never returned, free registration, and plane-session-only scope. No contradiction with annotations exists.

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?

Every sentence earns its place: purpose, prerequisite, idempotency, secret semantics, billing, and session constraint. The content is front-loaded with the core purpose and structured so an agent can quickly extract the critical usage rule.

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?

Despite lacking an output schema, the description states the returned identifier and its purpose. It covers prerequisites, retry safety, optional parameter behavior, billing, and session scope, leaving no operational gap for invoking the tool 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 coverage is only 33%, so the description carries the burden for `url` and `secret`. It explains `url` as the idempotency key and `secret` as an optional verification mechanism with generated fallback. The schema documents `plane_api_key`, so all parameters are meaningfully covered.

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 states a specific verb and resource: 'Register the delivery target a watch fires to'. It also names the downstream consumer, `watch_company`, and the key return value, `webhook_endpoint_id`, which makes the tool's role unambiguous and distinct from 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?

Provides explicit invocation guidance: 'call this first if you do not already hold one' and explains that `watch_company` follows. It also clarifies safe retry behavior via idempotency and billing implications, giving an agent clear conditions for when and how to use the tool.

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