identity_sandbox_register

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

Beyond the annotations, the description adds genuinely useful operational context: a rate limit of 10 per IP per hour, the fact that results are signed with a separate key (identity_jwks sandbox=true), and the warning that sandbox identities are never reported as verified. The closing 'Behavior: writes state upstream (not read-only)' sentence largely restates readOnlyHint=false, so it adds little, but the surrounding context is substantive.

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?

It is front-loaded with the 'START HERE' cue and the follow-up chain appears in the first two sentences. Some content is duplicated, though: 'Use a real wallet for an accountable identity' repeats the point already made in 'never reported as verified' and again in 'Not for production verification', and the 'Behavior:' line restates annotations.

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 fully covers what comes back (sandbox wallet plus sandbox_token), what to do next, the rate limit, and the safety caveat about sandbox keys. An agent has everything it needs to call this correctly and interpret the result.

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 the baseline is 4 and there is no parameter semantics to explain. The description appropriately spends its words on outputs and follow-up steps instead of inventing input details.

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 a specific action and its unique scope: it registers a sandbox identity and returns a sandbox wallet plus a sandbox_token, with no signing or request body needed. It also implicitly separates this tool from identity_register by pointing to real wallets for accountable identities, so an agent can choose between the two without opening either 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?

It gives an explicit trigger ('Use when you have no wallet and want a sandbox identity to test the flow'), an explicit exclusion ('Not for production verification, which needs a real wallet signature'), and names the follow-up tools to call (identity_get_challenge, identity_submit_response). Nothing about when or when not to use this tool is left to inference.

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