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

Annotations already declare readOnly and non-destructive, and the description is consistent with them while adding valuable context: the invoice amount is fixed at exactly 2,000 sats and no state is mutated (no signing, reserving, settling). It omits what the authorization result looks like and any auth/prerequisite 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?

Two tightly constructed sentences with the positive action front-loaded and the negative scope trailing. No filler.

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?

With no output schema, the description still conveys the key output fact (a 2,000-sat invoice authorization) and full side-effect scope. Minor gap: return shape and whether the caller must pass the result to another tool for signing/creation.

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 0%, so the description must carry the parameter meaning. It adds that the input is a name@frontiercrown.com identifier subject to normalization, but does not clarify whether the caller passes the full identifier or only the local part, nor how normalization changes it.

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?

Names specific verbs (check, normalize, prepare) and the exact resource (a name@frontiercrown.com NIP-05 invoice authorization), and implicitly separates itself from the create_* sibling by stating it prepares rather than creates.

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 explicit 'does not sign, reserve the name, create, pay, or settle an invoice' clause tells the agent the boundary conditions and routes genuine creation/payment to the create_* siblings. It stops short of naming the alternative tool directly, so it is strong but not fully explicit routing.

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