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

With no annotations, the description carries the full behavioral disclosure burden, and it does so well by explaining that the server never sees the private key, the keypair must be generated locally, and enrollment behavior differs by domain presence. It does not describe return values or failure/duplicate registration behavior, which prevents a 5.

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?

The description is front-loaded with the most important constraint: local script execution and key handling. It is information-dense but repeats the server-never-sees-the-key point twice, which is slightly redundant.

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 registration tool with no output schema, the description covers prerequisites, security posture, and both enrollment modes. It omits return format and failure cases, but the combination of schema and narrative is sufficient for an agent to invoke the tool correctly in typical cases.

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 100%, so the baseline is 3. The description adds useful context about domain-based naming and no-domain derived handles, but it does not add significant parameter-level detail beyond what the schema already provides.

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?

Description states a specific action and resource: 'Register a public key.' It also distinguishes itself from sibling read/verify tools by noting those do not require local script execution, so an agent can tell it apart from the other tools.

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 description explicitly contrasts this tool with 'read and verify tools' on the local-script-execution requirement, giving clear when-to-use guidance. It also defines two concrete usage paths: no domain for immediate enrollment with a derived handle, or a domain to claim a name.

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