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

readOnlyHint=true is consistent with the description, and the description reinforces it with concrete, valuable detail: no charge is incurred and it reports price_cents plus whether the balance covers it. That is real context beyond the annotation, though it omits details such as rate limits or whether quoting validates the source files.

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 with zero waste; the cost-free behavior is front-loaded and the return fields are summarized in a single clause.

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?

With readOnlyHint supplied, a full output schema, and 100% parameter coverage, the only burden on the description is the non-obvious cost-free behavior, which it states clearly. An agent can call this correctly from what is given.

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 enums and defaults documented for product, language, encoding, audit_targets and files. The description adds no parameter-level meaning beyond that, so the 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+resource ('price an audit') and adds the key distinguishing trait that nothing is charged, which separates it from the sibling submit_audit. It stops short of naming that sibling explicitly, leaving the reader to infer the pairing.

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?

'Without charging anything' implies a pre-flight/dry-run role before submit_audit, but the description never says when to call this instead of submit_audit or get_balance, nor that it must precede submission. The when-to-use signal is present but only implied.

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