list_parts

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

With no annotations, the description carries the full burden; 'list' implies a read operation, and it helpfully discloses the exact output shape ('one line for each part: "MPN (manufacturer): N documents"'). It omits whether results are paginated, how large the store may be, or whether the listing is scoped to the current project, so behavioral disclosure is partial.

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?

Three tight sentences: what it returns, the exact row format, and the alternative. Front-loaded with the payload and free of 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 values need not be explained, yet the description still specifies the row format. For a zero-parameter read tool with sibling routing included, nothing an agent needs in order to call it correctly is missing.

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?

Zero parameters, so the schema baseline of 4 applies and there is no parameter semantics to compensate for. The description adds no misleading parameter hints.

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?

Names a specific resource (parts in the store) and the exact data returned per row (MPN, manufacturer, document count), which is far more than restating the name. It also explicitly contrasts itself with list_documents, so an agent can distinguish the two without opening schemas, though the phrase 'the store' is never anchored to a concrete scope.

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?

The final sentence routes the agent to the correct alternative for document-level data ('list_documents gives the documents of a part'), giving clear selection context. It stops short of stating exclusions or prerequisites (e.g., whether a project must be loaded first), but the sibling routing is explicit.

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