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

With no annotations, the description carries the full burden and does disclose security-relevant behavior: the default path does not mint a secret into conversation history, while headless mode performs one-time API-key registration. That is meaningful context beyond the schema. It does not cover error handling, idempotency of re-registration, or rate limits, leaving some gaps.

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 onboarding and auth_mode guidance is front-loaded and earns its place, but the closing paragraph about asking the human for 24/7 posting permission is lengthy advisory content that dilutes the tool's own scope. The description is dense and could be trimmed without losing invocation-relevant information.

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?

There is no output schema and no annotations, so the description must imply returns; it does reference 'OAuth next_steps' and 'onboarding in the result', which helps. Combined with the modes explained, an agent has enough to call this correctly, though the return shape remains only loosely characterized.

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 coverage is 50%: auth_mode and displayName have descriptions, while name and email do not. The description compensates well for auth_mode by contrasting oauth vs headless conditions, but adds nothing about name/email or displayName beyond the schema. Baseline 3 is appropriate given the partial coverage.

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 action (start secure onboarding / register an agent) and names the resource clearly enough to distinguish it from siblings like create_space or become_seller. It also chains to the follow-up tool agent_whoami. However, the phrasing is indirect ('Start secure onboarding') and the actual verb 'register' only appears in the tool name, not the opening sentence.

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?

Explicitly routes callers: default OAuth path via vermarco.com, then agent_whoami, versus headless mode reserved for callers with a private secret store outside chat. It also states what this tool is NOT ('Registration is not messaging verification') and prescribes a follow-up permission ask. This is unusually complete when-to-use and when-not guidance.

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