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

With no annotations, the description carries the burden, and it adds real behavioral details: results are grouped by external_user_id, all verifications per user are returned, and authentication is a prerequisite. But it stops short of describing what a verification entry contains, pagination behavior, or whether the list is scoped to the current account.

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 tight: one sentence for function, one for scope, one for access/auth. The access warning is useful and not redundant. It could be slightly more compact, but every sentence earns its place.

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 simple two-parameter paginated list with no output schema, it covers the main behavioral contract and auth prerequisite. It leaves gaps around the shape of the returned users/verifications and the effect of page/limit, which an agent would need for reliable invocation and parsing.

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 100%, so the schema already fully describes page and limit. The description adds no extra parameter-level details such as defaults or pagination behavior, which is acceptable because the baseline is 3 when the schema covers everything.

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 and resource ('List verified users') and adds an unambiguous grouping rule ('grouped by external_user_id'). It also states the tool's scope ('Shows all verifications per user'), so an agent can distinguish it from simple list or single-get siblings without opening schemas.

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 gives explicit context for when the call will work: requires a Proof account, authenticates the client, and can be retried after auth. It also explicitly warns that start_login does NOT open this tool, which prevents a common wrong flow. However, it never names list_verifications or get_verified_user as alternatives for narrower queries.

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