calculate_bom_cost

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

With no annotations, the description must carry the full behavioral burden. It usefully discloses the fee model (Basic parts ¥0 feeder fee vs Extended parts +¥20/type) and that it emits optimization suggestions, but says nothing about permissions, failure modes when a part cannot be matched, or response shape.

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?

Two tightly packed sentences with no filler; the primary purpose leads and the fee-model detail follows, so an agent gets the essential meaning from the first clause.

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 single-parameter compute tool with no output schema, the description conveys the pricing rules and the optimization-suggestion behavior, which is most of what an agent needs. It stops short of describing the returned breakdown structure, which would require an output schema or explicit mention.

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% with a single well-documented `queries` array, so the schema already carries parameter meaning. The description adds no format or constraint detail beyond what the schema provides, making the baseline 3 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?

The description names a specific verb and resource ('Calculate PCBA component cost breakdown') plus a secondary function (JLCPCB SMT surcharge estimation), which is far more informative than the tool name alone. It does not explicitly contrast itself with `search_lcsc_parts`, so it stops short of full sibling differentiation.

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 only implied: an agent can infer this is a costing step after parts are identified, but there is no explicit when-to-use, when-not-to-use, or prerequisite statement (e.g., that component identifiers must first be resolved). No alternatives are named.

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