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

With no annotations, the description carries the full behavioral burden and does so well: it discloses an irreversible state change (frozen from this call on), the downstream effect on sale_update (refuses the document), the effect on rendering (signing copy, no DRAFT watermark), and a concrete quota (free tier: 5 finalized documents). That is exactly the mutation, side-effect, and limit information an agent needs before calling.

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?

One tight sentence with a colon that front-loads the outcome (ready to sign) before the consequences, plus a short quota sentence. Every clause earns its place: freeze, sale_update refusal, render change, and tier limit.

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 state-transition tool with no annotations and no output schema, the description covers the mutation, its irreversibility, downstream effects, and rate/quota limits. It could add whether the call is idempotent on an already-finalized document or the failure mode when the free-tier cap is hit, but nothing essential 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?

There is a single parameter (sale) with 100% schema description coverage, including a format example (BOS-2026-0001). Per the calibration baseline, the schema does the heavy lifting here and the description adds no additional parameter meaning, so a 3 is appropriate.

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 (Finalize) and resource (bill of sale) and immediately characterizes the resulting state: ready to sign. It also distinguishes itself from siblings by noting sale_update will refuse the document afterward and sale_render will emit the signing copy, so an agent can tell it apart from those tools without opening their schemas.

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 makes the use context clear (once finalized the document is frozen and becomes the signing copy) and effectively rules out sale_update as a follow-up path. It stops short of an explicit when-to-use/when-not statement or naming an alternative for un-finalizing, but the implied usage is unambiguous.

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