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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the description. The description adds only workflow context, not behavioral detail such as what a failure looks like, whether diagnostics/line numbers are returned, or where the policy is checked against. Useful but thin beyond 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 sentences, zero filler, with the action stated first and the usage trigger second. Every clause carries information an agent can act on.

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 one-parameter read-only tool this covers the essentials, and annotations plus schema carry the rest. However, no output schema exists and the description never says what validation produces (pass/fail only, structured errors, line references) or what happens on invalid input, leaving a real gap for an agent interpreting results.

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 is a single required parameter with 100% schema description coverage ('The whole policy TOML document, as written'), so the schema already does the work. The description's phrase 'policy TOML document' merely echoes the schema without adding format, size, or partial-document constraints. Baseline 3 applies.

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 pair: 'Check a policy TOML document.' The name and description agree, and the resource (a policy TOML document) is unambiguous. It does not explicitly distinguish itself from the closest sibling, get_default_policy, so a 5 is not warranted.

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 concrete timing guidance: 'after editing a policy file, before committing it.' That tells the agent when to reach for it in a workflow. It names no alternative tool or exclusion case, which keeps it short of a 5.

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