create_webhook_subscription

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

With no annotations, the description carries the full behavioral burden; it usefully covers the auth prerequisite and the accepted data types. It omits other mutation traits an agent would want — whether duplicate subscriptions are allowed, whether a verification handshake must succeed before deliveries start, and whether the operation is idempotent.

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 dense sentences with the purpose and the auth prerequisite front-loaded, then the value list. The enumeration is long but earns its place because it substitutes for missing enums in the schema; the only redundancy is slight overlap in the data-type naming scheme.

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 4-required-parameter mutation with nested objects, no annotations, and no output schema, several essentials are missing: the structure and allowed values of event_type, and any description of what the creation returns. The auth requirement and data_type domain partially cover the gap.

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 50%: callback_url and verification_token are already documented in the schema, while data_type and event_type are bare objects. The description compensates for data_type by enumerating valid values, which is real added meaning since the schema has no enums, but event_type remains completely unexplained in both places.

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 opens with a specific verb+resource ('Create a new webhook subscription') and states the benefit ('receive notifications when data changes'), so the agent immediately knows what the tool produces. It does not explicitly contrast itself with siblings like update_webhook_subscription or renew_webhook_subscription, so it falls short of a 5.

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?

It discloses a real precondition ('Requires OURA_CLIENT_ID and OURA_CLIENT_SECRET environment variables'), which tells the agent what must be true before calling. However, it says nothing about when to create versus update, renew, or reuse an existing subscription, leaving the sibling routing entirely to inference.

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