search_distributors

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

With no annotations, the description carries the burden and does well: it discloses the NOT ORDERABLE marking of obsolete parts, the per-result source attribution, the requirement of a personal API key per distributor, the note-with-steps behavior, and the up-to-50 result cap. It does not mention rate limits or failure modes for a distributor whose API errors out.

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 outcome (what a result contains), then moves to eligibility, key requirements, and fallbacks — a sensible order. It is somewhat long and the hard line breaks plus the imperative 'Give the note to the user' make it read like a handoff memo rather than a definition, but no sentence is pure filler.

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?

An output schema exists, so return formatting needn't be restated; within that constraint the description covers the prerequisites (keys, config source), the degradation path (notes, then part_links), and the result semantics an agent needs to act on the output 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 coverage is already 100%, so the baseline is 3; the description adds meaning by explaining that mpn may be a base part whose concrete MPNs are enumerated, and that distributor enablement is driven by the project file or global configuration. That is genuine context beyond the field descriptions.

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 and resource (search orderable parts at enabled distributors) and enumerates exactly what each result carries: lifecycle state, stock, prices, package, datasheet URL. An agent can tell this apart from part_links (link fallback) and get_ordering_codes without opening either schema.

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 concrete jobs to use it for (selecting the concrete MPN of the BOM, checking orderability) and spells out the fallback path when no API keys exist. It does not explicitly contrast with get_ordering_codes or project_availability, which is the one missing routing hint.

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