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

With annotations already disclosing openWorldHint=true and destructiveHint=false, the description goes further: it reveals the external approval step at AgentID, the 10-minute expiry, the single-use nature of pickup_code, the returned values (address, connector_key), and the ownership state. This is rich behavioral context well beyond structured fields.

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?

Front-loaded with purpose, then the call sequence, with minimal waste. The closing lines about the card and 'no owner' are slightly peripheral but still frame the outcome and sibling relationship, so they roughly earn their place.

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?

No output schema exists, and the description compensates by naming both call returns (sign_in_url/pickup_code, then address/connector_key). For a three-param, zero-required auth tool, everything an agent needs to invoke it correctly is present.

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 100%, so the baseline is 3, but the description adds real semantics: it explains that omitting pickup_code selects the first-call flow and that pickup_code must be reused exactly once within 10 minutes. That clarifies how the parameters drive the state machine beyond the schema's terse field notes.

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 verb and resource ('sign in with AgentID to get a Wayza address, or a new key for the address that inbox already has'), and the closing reference to register_agent ('you are an AI with no owner, as with register_agent') helps separate it from that sibling. An agent can tell what this does without opening the schema.

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?

Gives an explicit two-call protocol: call with no pickup_code to get sign_in_url and pickup_code, open the URL and approve, then call again with the pickup_code once within 10 minutes. It specifies the triggering condition, the sequence, and the constraint, leaving little to inference.

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