pad

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

With no annotations provided, the description carries the full burden. It discloses failure conditions (unconstrained sketch, invalid solid) and states that the tool always reports volumeBefore/volume/isValid/boundingBox to confirm actual material addition. This goes beyond the schema, which does not explain the meaning of these output fields.

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 description is well-structured: a clear purpose statement, followed by failure conditions and output validation, then a list of arguments. It is not overly verbose and front-loads the key information. The argument list is plain text but remains readable and efficient.

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?

For a complex CAD operation with 7 parameters and no annotations, the description covers the essential aspects: purpose, preconditions, failure modes, and parameter meanings. It also mentions output validation. It does not elaborate on the output schema structure (already present in the schema) or prerequisites like document/body existence, which are implied by parameter names. Overall, it is complete enough for an agent to use 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 description coverage is 0%, so the description must compensate, and it does thoroughly. It explains all 7 parameters: doc_name, body_name, sketch_name, name, length (in mm), midplane (symmetrical extrusion), and reversed_ (flip direction). Each parameter gets a meaningful explanation, making the tool usable without additional documentation.

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 a specific action: 'Extrude a fully-constrained sketch into a solid (PartDesign::Pad).' This distinguishes it from sibling tools like pocket (which removes material) and other feature tools. The mention of 'PartDesign::Pad' anchors it to a specific CAD feature type.

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: it is for adding material via extrusion, and it fails under specific conditions (sketch not fully constrained, invalid solid). It also indicates the tool is for cases where you need to verify material was added via the reported volume. However, it does not explicitly contrast with alternatives like pocket or state when not to use it.

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