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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: it is a static reference lookup requiring no input, returns a fixed OS/version array, and should never be guessed at. It does not mention caching or freshness of the list, which is the only real gap.

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 opening sentence is well front-loaded, but the body is padded: the validation guidance is repeated across 'When to use this tool' and 'LLM usage guidelines,' and a full JSON example is shown even though an output schema already exists. The headers add structure but the content is roughly twice the necessary length.

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 lookup with an output schema, the description is more than sufficient: it explains the call ordering relative to `linux_audit` and the validity-checking role. The example output partially duplicates the output schema, but nothing an agent needs to invoke it correctly 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?

The tool takes zero parameters, so the baseline is 4. The description confirms 'This tool does not require any input,' which is consistent with the empty schema, though it adds no further semantic detail beyond that.

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 first sentence states a specific verb and resource ('List supported Linux operating systems and their corresponding versions') and explicitly ties it to the `linux_audit` sibling tool. An agent can distinguish it from every other sibling in the list without opening a schema.

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 gives explicit when-to-use conditions (user doesn't know supported OS names/versions, ambiguous OS info, need to validate before an audit) and states a sequencing rule: call this before `linux_audit` when parameters are uncertain. The 'do not guess' instruction further routes behavior.

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