validate_scad

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

With no annotations, the description fully discloses behavioral details: it runs OpenSCAD with output to /dev/null, captures and categorizes messages from stderr, and returns a structured dict. This goes well beyond basic schema information and gives the agent a clear expectation of side effects and output.

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 with a concise summary followed by a clear Args section and return value description. Every sentence adds value, and the length is appropriate for the tool's complexity.

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 the tool's moderate complexity, the description covers all necessary aspects: purpose, usage, parameter semantics, behavioral nuance, and return format. The presence of an output schema does not diminish the completeness, as the description still explains the return dict and edge cases (e.g., message categorization).

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?

Despite 0% schema description coverage, the description explicitly explains each parameter (scad_content, scad_file, variables, include_paths) and notes the mutual exclusivity of scad_content and scad_file. This fully compensates for the sparse schema and provides operational guidance beyond mere names.

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 tool's function: 'Syntax-check OpenSCAD code without performing a full render.' This specific verb+resource pairing distinguishes it from sibling tools like render_single and render_perspectives, making its purpose unambiguous.

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 description provides clear usage context by contrasting with full renders ('Much faster than a full render') and stating it only parses/evaluates code. However, it does not explicitly name alternative tools or list exclusion scenarios, so it stops short of full alternative guidance.

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