Create a webhook subscription

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

The description adds a behavioral constraint: the endpoint must respond with 2xx within 5 seconds. Annotations include idempotentHint=true and openWorldHint=true, but the description provides additional context beyond these annotations. No contradiction.

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?

Two sentences, front-loaded with the core action, no wasted words. Efficient and clear.

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?

The description is self-contained for a create operation, but lacks information about the return value (no output schema). However, the schema and annotations provide additional context. Minor gap, but overall adequate.

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 80%, so the schema covers most parameters. The description does not add new meaning beyond what the schema provides (it mentions endpoint and event types but not in detail). The baseline is 3 due to high coverage.

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 clearly states the verb 'Subscribe' and the resource 'HTTPS endpoint to receive Lob event notifications', with specific examples of event types. It distinguishes from sibling tools like list, delete, update.

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 by describing the subscription process but does not explicitly state when to use this tool versus alternatives like update or delete. It includes a requirement (2xx response within 5 seconds) but no guidance on when not to use it.

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