Set a single named property on a FreeCAD object, coercing lists into vectors for vector properties. Use it to update parametric design values during modeling.
Set a single property by name on an object. Coerces lists → Vector for Vector properties; other values pass through.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| value | Yes | ||
| handle | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It does disclose a genuine behavioral trait beyond the schema — list values are coerced to Vector for Vector properties and other values pass through — which is useful. But it omits error behavior, whether the property must pre-exist, permission requirements, and reversibility of a mutation.
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?
Two short sentences, front-loaded with the core action and followed by the one non-obvious behavior. No padding, though the brevity is at the edge of under-specification rather than being exemplary economy.
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?
A mutation tool with zero annotations, no output schema, and 0% schema description coverage needs the description to fill more gaps than it does. Nothing is said about return value, failure modes, or valid object/property states, leaving the agent under-informed for a write operation.
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. It partially does: 'by name' clarifies the name parameter identifies the property, and the coercion sentence explains how the value parameter is interpreted. The handle parameter and value type constraints remain unexplained, so compensation is only partial.
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 gives a specific verb+resource ('Set a single property by name on an object') and scopes it to one property per call. It does not, however, name or differentiate from any sibling (e.g., get_object, transform, boolean_op), so the agent must infer where this fits in the CAD/geometry toolset.
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?
There is no statement of when to use this tool versus alternatives, no prerequisites (e.g., object must exist or handle must be registered), and no mention of any related tool. The agent gets no routing guidance at all.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.