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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds a genuinely non-obvious security caveat — that retrieved keys are not themselves a trust anchor — which is behaviorally important and not derivable from annotations. It stops short of describing return format or freshness/rotation characteristics.

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 sentences with zero filler, and the core capability is front-loaded before the caveat. The second sentence is terse to the point of being cryptic on its own, which slightly undercuts an otherwise efficient structure.

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 and no annotations about authentication or freshness, the description is the only place an agent could learn what comes back (key format, fingerprint encoding, rotation) and whether any auth is required. It names the two returned artifacts but gives no shape or usage path, leaving gaps for a security-critical discovery call.

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 no parameters, so there is nothing for the description to disambiguate; the baseline for a zero-parameter schema applies. No parameter-related claims are made, correctly.

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 (discover) and resource (current Ed25519 public key and fingerprint), which separates it from the attestation-verification siblings that consume such keys. It does not name any sibling explicitly, so the distinction from network_state_attestation or verify_network_state_attestation is inferable rather than stated.

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 clause 'Discovery is not an independent trust anchor' implies the key must be corroborated through an attestation tool, but it never says so directly or names which sibling to use for that corroboration. Usage is suggested by security context rather than specified.

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