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

While annotations are absent, the description explicitly labels the operation as 'Safe, idempotent read-only' with no side effects, which is crucial behavioral context for an agent. It also states expected output, which is beyond minimal.

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 concise with three labeled sections, each earning its place: behavior, usage, and output. It is front-loaded with the safety information and is highly scannable.

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 zero-parameter, simple read-only tool, the description fully covers behavior, usage, and expected output. No output schema, but the description explicitly states what is returned, making it 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?

There are zero parameters, so the schema provides no parameter semantics. The baseline is 4 for zero-parameter tools, and the description correctly indicates no input is needed, aligning with this.

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?

The description states the tool obtains the public key for verifying server signatures, which is a clear verb+resource. It does not explicitly distinguish from siblings, but the purpose is specific enough given the sibling names suggest different functions.

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?

It provides a clear context for use: to verify server signatures offline with zero network calls. No explicit exclusions or alternatives, but the guidance is sufficient for the agent to know when to use it.

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