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

With no annotations, the description carries the full behavioral burden and does so: it declares read-only, discloses the self-pausing rule (pauses itself at 20 consecutive failures), states the auth requirement (Pro or Bot key from X-API-Key header or api_key argument), and notes that a missing key returns an error object rather than an exception.

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 purpose and scope are front-loaded, then field contents, then auth details, all in one paragraph. It is dense and information-rich with minimal filler, though the run-on field enumeration slightly compresses readability.

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?

With no output schema, no annotations, and one parameter, the description is complete: it documents return fields, delivery-health semantics, auth prerequisites, and error behavior. An agent has everything needed to call and interpret it.

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 0% and the schema only names 'api_key' with a null default. The description compensates well by explaining both sources (X-API-Key header or the api_key argument) and the consequence of omission, though it does not fully clarify the null default vs. explicit-supply behavior.

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?

It states a specific verb and resource ('The webhook alert subscriptions that belong to the caller's API key'), scopes it to the caller, and enumerates the returned fields. It also names a sibling, delete_alert, making it distinguishable without opening a schema.

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?

'Call it to find the id for delete_alert or to check why alerts stopped arriving' gives explicit use conditions tied to concrete tasks. It routes the agent toward the correct follow-up tool rather than leaving usage to inference.

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