verify_identity

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does describe the return behavior (session URL or instant verification) but omits potential side effects, such as whether this is a permanent write operation, requires authentication, or has external consequences. The description is partially transparent but lacks depth.

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 two sentences long, front-loaded with the core action, and contains no redundant information. Every word contributes to understanding the tool's purpose and key behavior.

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?

The tool is relatively simple with only two parameters and no output schema, so the description need not be lengthy. It covers the main return value (session URL) and the passcode alternative. However, it does not mention any prerequisites, failure conditions, or that starting KYC verification may have side effects, leaving some contextual gaps.

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?

The schema already provides descriptions for both parameters (user_id as 'Freeplay user UUID' and passcode as 'Optional sandbox passcode'). The description adds no new meaning beyond what the schema already states, only restating the sandbox passcode option. With 100% schema coverage, a baseline score of 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 clearly states the tool's action: 'Start KYC verification.' It also specifies the return value (a Veriff session URL) and the alternative instant verification with a passcode, which distinguishes it from sibling tools like status or register.

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 description implies a clear use case (initiating KYC verification) but provides no explicit guidance on when to use this tool over alternatives, nor any exclusion criteria. There is no reference to sibling tools or conditions under which this tool should not be used.

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