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

Annotations alone would only say this is a non-open-world read, but the description explains the real mechanics: it returns one curl command per file plus routing, each upload yields a file_id that must be passed downstream, and commands are run via a shell tool or handed to the user. It also discloses the 20 MB cap and the Maglev API key requirement, which no annotation field covers.

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?

The trigger condition and the input-type list are front-loaded, and each subsequent sentence carries distinct operational information (path requirement, curl output, shell execution, file_id handoff, API key, sibling exclusion). It is dense and slightly run-on for a single paragraph but has no filler sentences.

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?

With no output schema, the description fully covers what comes back (curl commands, routing, file_id per upload) and what to do with it, including the no-shell fallback. Prerequisites, size limits, and the next tools to call are all stated, so nothing an agent needs in order to invoke this 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?

Schema coverage is 100% for the single array parameter, so the baseline is 3; the description adds real meaning by specifying these are paths on the user's local machine, that there is one entry per file, and that fabricated names are not acceptable. It stops short of stating format or ordering rules, but it goes beyond the schema text.

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 ('start a quote from CAD files') and enumerates the accepted inputs (STEP/STP for CNC, sheet metal, injection molding; JSON wire-harness spec). It actively distinguishes itself from siblings by naming search_parts for off-the-shelf parts and by naming check_manufacturability and get_quotes as the downstream consumers.

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?

It states the triggering condition ('when the user wants a custom part made or quoted from CAD'), positions itself as 'first step of the quoting flow', and gives explicit exclusions ('not for off-the-shelf parts: use search_parts'). It also handles the edge case of a missing file path: ask the user, never invent a filename.

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