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

Annotations only indicate the operation is not read-only, not idempotent, and not destructive, so the description carries the burden of explaining side effects. It goes well beyond that: the document becomes frozen, sale_update refuses it, later renders omit the DRAFT watermark, and a free-tier limit of 5 applies. This is rich, useful behavioral disclosure.

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 two sentences with no filler. The first sentence front-loads the core purpose and the most important behavioral consequence, and the second efficiently adds the quota constraint. Every sentence earns its place.

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 mutating tool with no output schema, the description covers the essential facts an agent needs: what finalize does, the irreversible freeze, downstream effects on update and render, and the quota. Nothing critical appears missing for correct invocation.

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 already fully documents the only parameter, 'sale,' including its type, maximum length, and an example value. The description does not add parameter-specific detail beyond identifying the bill of sale, so baseline 3 is appropriate given the 100% schema coverage.

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 and resource: 'Finalize a bill of sale so it is ready to sign.' It also distinguishes itself from sibling tools by explaining that the document is frozen, sale_update refuses it afterward, and renders become the signing copy. There is no ambiguity about what operation is performed.

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 makes the usage context clear: it is the step that makes a bill of sale ready for signing, after which updates are refused and renders use the signing copy. It does not explicitly name alternative tools or state 'use when X, not Y,' but the lifecycle context is strong enough to guide correct selection.

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