parts_search

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description isn't required to restate that. It adds genuinely new behavioral context: the tool depends on an undocumented endpoint, and a failure indicates the endpoint changed rather than a missing part — a non-obvious trait an agent cannot infer from annotations or schema.

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 sentences, no filler. The purpose and returned fields come first, with the endpoint-fragility caveat second — well front-loaded and every clause earns its place.

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-shape detail is optional, and the failure-mode disclosure closes the main operational gap. The only shortfall is the absence of selection guidance against sibling search tools, which keeps it just short of complete.

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 67%: keyword and limit are documented in the schema, while in_stock_only carries only a default with no explanation. The description enumerates return fields rather than adding input-side meaning, so it does not compensate for the undocumented parameter. Baseline 3 is appropriate given partial schema coverage.

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 ('Search') and a precise resource ('JLCPCB's assembly parts catalogue'), then enumerates what the results contain (LCSC code, MPN, package, stock, basic-part flag, unit price). This clearly separates it from the KiCad-library siblings like lib_search and lib_index, which operate on a different catalogue entirely.

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?

There is no statement of when to reach for this tool versus the similarly named lib_search, nor any prerequisites (e.g. that keyword must be an MPN or value+package). The only contextual guidance given is a failure-mode note, which is about diagnostics, not tool selection.

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