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

With no annotations, the description carries the full burden; it does disclose two important behavioral traits: the invite is single-use and expires in 48h, and it produces an accept_url to deliver out-of-band. It omits who is authorized to mint invites, whether minting supersedes an existing guardian, and what happens on expiry or re-invocation.

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?

Two short sentences, front-loaded with the action and its key constraints (single-use, 48h), followed by the operational instruction. No wasted wording.

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 zero-parameter tool with no output schema, the description covers the essential output (accept_url) and the invite's lifetime. Minor gaps remain around guardian lifecycle and error behavior, but nothing that would prevent a correct call.

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 takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The description correctly implies no inputs are 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?

The description uses a specific verb ('Mint') and a well-defined resource ('single-use invite'), and states the outcome precisely: a human becomes this agent's withdrawal guardian. It does not mention the sibling guardian_status, so the boundary between inviting a guardian and checking guardian state is left to inference.

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?

It implies the usage context (setting up a withdrawal guardian) and gives a concrete next step, 'Hand them the accept_url.' However, it never states when not to call it, whether it can be called repeatedly, or how it relates to guardian_status or prepare_withdrawal.

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