nexus_start_age_verification_flow

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

Annotations already set readOnlyHint=false, so the description's 'ACTION, not a read' reinforces that but adds meaningful context about initiating a verification session and returning a URL to open. This is sufficient for an agent to understand the tool's side-effectful nature.

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 concise, front-loaded with the core purpose, and every line adds value: what it does, that it is an action, and what it returns. No filler or redundant content.

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 no-parameter action tool with an output schema, the description is complete. It conveys the operation, side-effect nature, and the return shape with a clear instruction to open the returned URL.

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 tool has zero parameters, and the schema already documents this fully. The description appropriately indicates the operation targets 'the current user,' which is useful context even though no explicit parameter is needed.

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?

Description clearly states the specific action: 'Start the age verification flow for the current user (v2 GraphQL).' It also emphasizes this is an ACTION that initiates a session, distinguishing it from read-only verification info tools.

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 gives some guidance by explicitly saying 'This is an ACTION, not a read,' which helps rule out read-only verification lookup tools like nexus_get_age_verification_info. However, it does not differentiate from the closely related sibling nexus_start_age_verification_appeal_flow or state when one should be preferred over the other.

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