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

The annotations say readOnlyHint=false and idempotentHint=false, and the description richly confirms and expands on this by explaining that the call upgrades the session in place, requires no reconnect, returns secrets exactly once, and that re-calling mints a new identity. It also clarifies Bearer auth only applies to new connections. This goes well beyond the structured annotation data and gives an agent a realistic model of side effects and persistence requirements.

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 dense and front-loaded, opening with the most actionable fact: no API key needed, call now. Most sentences earn their place, covering session upgrade, one-time secret display, persistence, and re-onboarding hazard. There is minor redundancy around the secrets being shown once and the no-credential point, which prevents a perfect conciseness score.

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 tool with 15 optional parameters, the description covers the onboarding flow, authentication expectations, return-value sensitivity, persistence obligation, and post-call sequence. Since an output schema exists and the input schema documents all parameters, nothing critical is left unexplained. References to confirm_keys_persisted and money tools add practical operational context.

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%, and every parameter has a detailed schema description, so the description does not need to repeat parameter semantics. The description adds no direct parameter-level information beyond hinting that an empty request like REST POST /api/v1/onboard {} is valid. This matches the baseline for a schema that already carries full parameter documentation.

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 states exactly what the tool does: obtains an A2AWire API key by minting a provisional agent identity and returning api_key, owner_key, and wallet_private_key. It is specific about the resource and the action, and clearly separates itself from ordinary authenticated calls by noting no API key or Authorization header is needed. The warning that re-calling mints a new identity further pins down the tool's exact role.

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 strong when-to-use guidance: call first if connected with no key, call on the open session, and call before using money tools. It also provides a when-not-to: do not re-onboard because re-calling creates a new identity. However, it does not explicitly compare itself to sibling onboarding alternatives or name conditions for choosing another tool, so it falls just short of full alternative routing.

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