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

Beyond the annotations (which only indicate a mutable, non-idempotent write), the description explains editing semantics, including that empty strings clear optional fields and that finalized documents are immutable. It does not discuss authorization, response payload, or error behavior, but the key behavioral constraints are disclosed.

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?

Three short sentences lead with the operation, then give the clearing convention, then state the immutable-state limitation. No filler or repetition.

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 broad update tool with 23 parameters and no output schema, the description covers what can be changed, the clearing convention, and the finalization gate. It omits auth/error/return details, but nothing essential for basic invocation 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 only 22% schema-description coverage, the description compensates by grouping parameters into meaningful categories (price, buyer, seller, item details, identifiers, as-is, warranty, notes) and adding the clearing rule for optional fields. It does not walk through every one of the 23 parameters, but the categories plus schema cover most practical needs.

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 opens with a clear verb and resource ('Change anything on a bill of sale') and states the lifecycle constraint ('not finalized yet'). It also enumerates the updatable field categories, which distinguishes it from sibling tools like sale_finalize and sale_create.

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 gives an explicit condition for use ('not finalized yet') and an explicit exclusion ('A finalized document cannot be edited'). It does not name alternative sibling tools, such as sale_finalize, so it falls just short of fully explicit routing.

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