create_identity_challenge

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

Annotations only say it is a non-read-only, non-destructive write, so the description carries the rest and does so well: it discloses that this is an asynchronous job whose outcome must be polled and enumerates the six terminal states (confirmed, denied, cancelled, failed, expired, revoked). It also flags the access prerequisite (PROOF_API_KEY plus restart) and explicitly notes that start_login does NOT unlock it, which is genuinely useful auth context.

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?

Three short, clearly labelled blocks: purpose first, then agent follow-up, then access prerequisites. Every sentence is load-bearing and the most important information (what it creates, how to poll it) is front-loaded.

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 compensates by explaining that an ID is returned and must be polled via get_identity_challenge until a terminal state, covering the return-value gap. Access prerequisites and failure states are covered; only the comparison against sibling challenge creators is absent.

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 circle_id, member_id and the suspicious_channel default. The description adds conceptual meaning for suspicious_channel (the channel contrast drives the cross-channel check) but no syntax or format detail beyond the schema, 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 ('Create a Proof-Me cross-channel identity challenge (CONFIRM)') plus the scope ('for an enrolled Circle member'), and the second sentence explains the mechanism (approval on a channel different from the suspicious contact's). It does not, however, differentiate itself from closely related siblings such as create_confirmation or create_multi_channel_verification, so the agent still has to infer which challenge creator to pick.

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 'Agent usage' line gives a concrete workflow (poll get_identity_challenge until the status leaves pending) and names the terminal states, which is real next-step guidance. But it never states when to choose this over the other verification/confirmation creators in the sibling list, so the when-to-use decision is only implied by the scenario description.

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