build_part_index

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

Even without annotations, the description fully discloses behavior: opens files read-only in series, saves locally, no network/telemetry, incremental based on mtime+size, rebuild and max_parts limits, and that it opens/closes documents requiring SolidWorks idle.

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?

Well-structured: summary sentence, then process details, then args list, then return fields. Every sentence adds value, no fluff. Front-loaded with the main purpose.

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?

Given no output schema, the description lists return fields. It fully covers how the tool works, what it produces, and edge cases (incremental, rebuild, max_parts). Complete for a file scanning/indexing tool.

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?

The description explains all three parameters (folder, rebuild, max_parts) in detail, providing meaning beyond the bare schema. It clarifies folder recurses and ignores temporary files, rebuild forces re-read, and max_parts is a cap per run.

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 clearly states the verb (index), resource (folder of .SLDPRT parts), and result (local catalog in mcp_cad_index.sqlite). It distinguishes from siblings by being a local indexing tool vs. modeling or query tools.

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?

Provides clear context for when to use (indexing parts locally), includes conditions (SolidWorks idle), and explains incremental behavior and rebuild option. Lacks explicit comparison to siblings like search_part_catalog, but the use case is well-defined.

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