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

Annotations only cover the safety profile (readOnlyHint, openWorldHint=false); the description adds the return payload (id, sku, name, unit, default sell price, isService), the meaning of isService for stock/costing, and the three outcome statuses. That is substantial behavior beyond what the annotations declare.

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?

Front-loaded with the core purpose, then scope, matching rules, return fields, and status semantics. Every sentence is useful, though the isService parenthetical is slightly wordy.

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 and minimal annotations, the description supplies the return fields, matching constraints, and status outcomes an agent needs to call and interpret this tool correctly.

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 0% and the single 'query' param is undocumented in the schema, so the description carries the burden and does so by specifying acceptable inputs (name, SKU, exact barcode) and their matching strictness.

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 (resolve) plus resource (product) and the accepted identifiers, scoped to an invoice line. It is clearly distinguishable from resolve_customer and resolve_vendor among the siblings.

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?

Gives practical selection guidance: plain names/SKUs work best, a barcode must match exactly, and it warns to never guess among ambiguous candidates. It stops short of naming alternative tools or stating when not to use it.

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