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

With no annotations, the description carries the full burden and does well: it discloses the DRAFT watermark safety behavior, the one-hour download-link lifetime, the stem-only semantics of out_path, and that it is free. It omits any auth/permission requirements and doesn't say whether the sale must be finalized to render without a watermark.

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?

Purpose is front-loaded in the first clause, followed by the differentiators (watermark, link lifetime, out_path semantics). Dense but every sentence adds a distinct fact; the trailing one-word 'Free.' is terse but informative.

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 no output schema, the description usefully explains the return value (a download link valid for one hour) and the naming behavior, and covers the draft/final watermark rule. Remaining gap is preconditioning: nothing states whether the sale must be finalized or what happens on an invalid id.

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%, so the schema already documents sale, format, out_path, and overwrite. The description restates the out_path-as-stem rule and format default rather than adding new syntax or edge-case meaning, so 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 (render) and resource (bill of sale) plus the exact artifacts produced: Markdown, self-contained HTML, or both. This is unmistakably distinct from the CRUD siblings (sale_get, sale_list, sale_update) without needing to name them.

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?

Usage is implied rather than stated: the DRAFT-watermark rule hints that this is meant for review copies before finalization, and 'Free' hints at a cost-free alternative to other rendering paths. But it never says when to call this versus sale_get/sale_finalize or whether a sale must be finalized first.

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