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

Annotations already mark this read-only and closed-world, but the description adds substantial behavior: the exact return fields, the three possible statuses (resolved/ambiguous/none), the explicit ambiguity directive, and the isService semantics ("selling it never counts stock or posts a cost"). With no output schema, this disclosure is genuinely valuable.

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-loads the core purpose, then adds return fields and status behavior. Dense but each clause carries information; the parenthetical isService explanation is long but earns its space by clarifying a non-obvious flag.

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 resolver with no output schema, the description covers purpose, input expectations, return shape, and the ambiguity-handling contract. An agent has everything needed to call it correctly and interpret the result.

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 coverage is 0%, so the description must carry the load. It does: the single `query` param is characterized as a product name or SKU, with "plain names or SKUs work best" implying the preferred input form. It doesn't specify matching rules or format edge cases, so not a full 5.

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) and resource (product) plus the concrete context (for an invoice line). It is cleanly distinguishable from the sibling resolve_customer and resolve_vendor by resource, and from update_product_draft by the resolve/read semantics.

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?

"for an invoice line" and "Plain names or SKUs work best" give clear usage context and input guidance, and the status handling ("never guess among candidates") steers behavior. It stops short of naming alternatives or stating when NOT to use this tool, so it falls short of a 5.

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