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

Annotations already declare idempotent=true, destructive=true, readOnly=false and closed-world, so the safety profile is partly covered. The description adds genuine context beyond them: the token is single-use against the previewed record state, expired/changed records force re-preview, and errors are non-acknowledgeable. It doesn't explain why this is flagged destructive (what state changes irreversibly) or whether unacknowledge_invoice_warning reverses it.

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?

Most sentences earn their place — the prerequisite is front-loaded and the expiry rule is tight. But 'Prepare acknowledging a current warning or information flag' is a stray, ambiguous sentence that appears to be preview boilerplate and adds no actionable information.

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 mutation with annotations and no output schema, the description covers the full call flow, token provenance, and failure semantics. It could say more about what success returns or the reversible counterpart (unacknowledge_invoice_warning), but nothing needed to call 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?

With one parameter, the description usefully constrains it to 'its confirmation_token only' and ties it to the preview output plus user confirmation. The embedded schema description also says the token must come from the operation's preview, so the pairing is reinforced rather than left ambiguous.

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 gives a specific verb-and-resource pairing (apply the change from preview_acknowledge_invoice_warning to acknowledge a warning) and names the sibling it depends on. However, the third sentence, 'Prepare acknowledging a current warning or information flag,' reads like preview-tool language and muddies what this tool actually does.

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 specifies an exact prerequisite (call preview_acknowledge_invoice_warning and have the user confirm), names the sibling, and states exclusions: changed or expired records require a new preview, and errors cannot be acknowledged or bypassed. An agent knows when to use this versus preview or unacknowledge.

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