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

Annotations already declare readOnly=false, openWorld=true, idempotent=false, and destructive=false. The description adds substantive context beyond them: storage prerequisite, one-time enrollment, browser-generated non-exportable P-256 key, and only public-key upload, though it omits expiration/error and return behavior.

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?

Three compact sentences front-load the create action, then state the prerequisite and key-handling behavior. Every sentence contributes useful context with 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?

For a one-parameter tool with no output schema and annotations covering safety traits, the description supplies the critical prerequisite and cryptographic behavior. It still leaves the label parameter and caller-facing result undefined, so it is strong but not fully complete.

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 sole optional parameter, label, has 0% schema description coverage and is not mentioned in the description at all. The schema gives type and length limits, but neither source explains what the label means or how it is used, so the description does not compensate for the coverage gap.

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, "Create," and a specific resource, "one-time trusted-device enrollment capability," so the agent can distinguish it from the pairing status sibling. "Capability" is slightly abstract, but the pairing/enrollment intent is clear.

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?

Adds a prerequisite that GhostKey persistent trusted-device storage must be configured and implies one-time enrollment use. It does not name alternatives such as ghostkey_device_pairing_status or say when not to use this tool, so usage guidance remains implied rather than explicit.

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