add_horizontal_constraint

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

With no annotations, the description must disclose behavioral traits. It does not mention that the tool requires an active sketch or that it modifies sketch geometry. The agent is left unaware of side effects or requirements.

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 extremely short, but it is under-specified rather than genuinely concise. It delivers no useful information, making it inadequate despite its brevity.

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?

The description is far from complete for a FreeCAD constraint tool with multiple siblings. It omits prerequisites, behavior, return values, and context for selecting this tool over alternatives.

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 input schema has 100% description coverage for its two parameters, describing sketch_name as 'Body name' and edge_index as 'Geometry index'. The tool description adds no additional meaning beyond the schema, so a baseline score of 3 is appropriate.

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 is 'FreeCAD tool: add_horizontal_constraint', which merely restates the tool name without specifying its purpose. It fails to indicate that this tool adds a horizontal constraint to sketch geometry, and provides no differentiation from sibling constraint tools like add_vertical_constraint or add_parallel_constraint.

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 gives no guidance on when to use this tool, its prerequisites, or alternatives. Sibling tools include several other constraint types, yet no information is provided to help an agent choose.

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