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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: the required auth scope (user:read) and the behavioral fact that these keys are injected into newly created servers — information an agent cannot get from the annotations.

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 short clauses with no padding, and the resource identification is front-loaded. It is efficient, though the fragment structure reads more like a note than a polished instruction.

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-param read tool this covers auth and the resource's role. With no output schema, however, the description does not say what a key record contains (name, fingerprint, dates) or whether pagination applies, leaving a modest gap in what the agent can expect back.

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 zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. Schema coverage is 100% and the empty schema is self-explanatory.

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 is a noun phrase ("SSH public keys on the account") and leans on the tool name/title for the verb 'list'. It does add a differentiating fact — the keys are installed on new servers — which separates it from add_ssh_key, but the core purpose statement is vague rather than a specific verb+resource declaration.

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?

"Needs user:read" gives a prerequisite, but there is no explicit when-to-use guidance and no named alternative (e.g., add_ssh_key for creating keys). The agent must infer usage entirely from the resource name and the incidental note about new servers.

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