list_verified_users

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

readOnlyHint already covers the safety profile, but the description adds genuinely useful context beyond it: the credential precondition (PROOF_API_KEY + restart) and the explicit warning that start_login does not unlock this tool. This avoids a common failed-invocation path.

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 core behavior is front-loaded in the first sentence, followed by compact access notes. No wasted words, though the two-line ACCESS block is slightly repetitive in tone.

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, the description usefully explains the grouping/return shape and the access prerequisite. It is complete enough for a simple paginated list tool, missing only page-size defaults and pagination edge behavior.

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 page and limit are already documented in the schema. The description adds nothing further about pagination limits or defaults, so the baseline 3 applies.

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?

States a specific verb and resource ('List verified users') and adds scoping detail ('grouped by external_user_id', 'all verifications per user'). This distinguishes it from the singular get_verified_user sibling, though it never names that sibling explicitly.

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 block gives an important precondition (needs a Proof account, PROOF_API_KEY must be set) and warns that start_login does not open this tool. However, it offers no guidance on when to prefer this over list_verifications or get_verified_user, so alternative routing is left to inference.

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