Sketch a line

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

With only the title as annotation, the description carries the burden of behavioral disclosure. It does disclose the key side effect (adds a sketch) and a key geometric limitation (no enclosed region, not extrudable), but it does not mention what the call returns, whether validation can fail, or other side effects.

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 with no filler; the action is front-loaded and the caveat earns its place by preventing a common misuse. Nothing could be removed without losing value.

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 simple sketch-creation tool, the complete parameter schema plus the added extrusion caveat give an agent enough to invoke it correctly. It could be more complete by describing the returned feature or typical construction-line use cases, but those are not required for correct invocation.

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?

All 9 parameters are already described in the schema, including the coordinate format for start/end and the enum for plane, so the baseline of 3 applies. The prose adds no parameter-level details beyond the schema.

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 uses a specific verb ('Add') and a concrete resource ('a sketch holding one line segment'), and it states a distinguishing consequence ('cannot be extruded') that separates it from closed-shape sketch tools. An agent can tell this tool creates line geometry rather than a circle or rectangle.

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 warning that a line encloses no region and cannot be extruded gives an implied when-not-to-use signal, but no alternative tools or explicit selection conditions are named. The usage context is inferable rather than stated.

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