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

With no annotations, the description carries the full behavioral burden, and it partially meets it by disclosing the 409 response on re-registration — concrete, non-obvious error behavior. It omits permission/auth requirements, whether the operation is idempotent beyond the 409, and what a successful registration returns or changes.

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?

A single compact sentence with the operation front-loaded and the notable error behavior trailing it; no filler or repetition. It is efficient, though the extreme brevity is closer to under-specification than to tight writing.

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 three-parameter mutation tool with no annotations, no output schema, and 0% schema coverage, the description is too thin: it supplies neither parameter meaning nor auth context nor a description of the result. The 409 note is the only substantive detail beyond the bare operation name.

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 compensate, and it does not: it merely restates the three parameter names in braces without explaining the format of issuer_id or public_key (e.g. key encoding) or the permitted values of issuer_class. An agent learns nothing about the parameters beyond their existence and requiredness.

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+resource ('Register an issuer') and enumerates the payload fields, so the operation is unambiguous. It does not differentiate from siblings, but none of them (attestation_check, dispatch, probe, receipts, verdict_lookup) overlap with registration, so there is nothing to distinguish.

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?

There is no statement of when to call this versus other tools, no prerequisites, and no mention of authorization or registration-order requirements. The only usage-relevant hint is the 409 duplicate case, which is a failure mode rather than guidance.

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