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

Annotations already declare readOnlyHint=true, and the description confirms a read-only list operation. It adds that the tool lists auth keys and API access tokens, and cites the REST endpoint, but it does not disclose default scoping (e.g., only the caller's own keys unless 'all' is true) or pagination behavior, which would be useful behavioral context beyond the annotation.

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 a single sentence that front-loads the core purpose ('List auth keys and API access tokens for the tailnet') and includes a useful REST endpoint reference. It contains no redundant or vague wording, earning a high score for conciseness.

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 simple tool with one optional parameter and no output schema, the description states the operation and the API path, which is largely sufficient. The parameter schema covers the 'all' behavior, and the read-only annotation is clear. However, it could be more complete by mentioning the default scoping (only caller's own keys) directly in the description, though this is already in the schema.

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 input schema has high coverage: the sole parameter 'all' includes a complete description explaining its effect. The tool description itself adds no parameter-specific context, but given 100% schema coverage, the baseline score of 3 is appropriate.

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 uses a specific verb 'List' and clearly identifies the resource as 'auth keys and API access tokens for the tailnet', distinguishing it from sibling tools like get_key, create_auth_key, and delete_key. The REST endpoint reference adds further precision.

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 description implies usage for listing all keys in the tailnet, but does not explicitly state when to use this tool over alternatives like get_key, nor does it provide exclusions or prerequisites. There is no mention of 'use get_key for a single key' or similar guidance, making the usage context only implicit.

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