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

With no annotations, the description carries the behavioral burden. It adds useful context beyond the schema: the tool requires authentication, has an access prerequisite, and the start_login flow is explicitly not a path to this tool. It also states that results include status, response codes, and timestamps. It does not mention rate limits or error behavior, but for a read-only list operation the coverage is solid.

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 description is compact and front-loaded: the core purpose is stated in one sentence, and the access warning is separated into a short, actionable block. Every sentence earns its place, and no information is repeated.

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 list tool with no output schema, the description adequately names the returned fields (status, response codes, timestamps) and the pagination/filtering behavior. The access/auth caveat is also covered. It could go further by describing the response envelope or pagination metadata, but nothing critical is missing for calling 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 description coverage is 100%, so the schema already documents page, limit, status, and event_type. The description only reinforces that filtering and pagination exist without adding parameter-level meaning beyond the schema. Baseline 3 is appropriate.

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 ('List') and resource ('webhook delivery attempts') and immediately clarifies scope: pagination, filtering, and the fields shown (status, response codes, timestamps). This distinguishes it from singular get_webhook_delivery and from retry_webhook_delivery without needing to inspect 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?

The ACCESS note gives concrete usage context: a Proof account is required, the client must be authenticated first, and start_login does NOT open this tool. It clearly tells the agent when it can be used, though it does not explicitly compare to sibling list/get tools.

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