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

Goes beyond the idempotentHint annotation by explaining that duplicate storage returns the existing key, and by noting that authentication is required and the return value is a key id. This adds meaningful context for how the tool behaves in practice.

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 sentences, front-loaded with the action and purpose, followed by idempotency and downstream integration details. Every sentence contributes value without 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 three-parameter tool with complete schema descriptions and idempotency annotations, the description covers the workflow, authentication requirement, and return value. Nothing essential for selecting or invoking the tool is missing.

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%, with clear descriptions for name, publicKey, and sessionKey, so the baseline of 3 applies. The description adds context about the returned key id but does not need to restate parameter details.

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 and resource: 'Store an SSH public key on your account' for injection into VPS installs. This clearly separates it from siblings like listMySshKeys and deleteSshKey.

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?

Gives clear when-to-use guidance: it is safe to call before every order and it returns a key id to feed into orderVps or buildVpsInstance. It does not explicitly mention alternatives or when not to use it, but the intended workflow is well specified.

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