measure_line

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

With no annotations, the description carries full burden. It discloses coordinate system (image px at render scale 2.0, origin top-left, y-down), scale requirement, and that sheet payloads carry dims in px and pt. It doesn't mention destructiveness or auth, but for a read-like measurement tool, these are less critical.

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, starting with verb and purpose, then key constraints. Every sentence adds value (coordinate details, scale requirement, condition usage). It could be slightly tightened (e.g., merging coordinate and sheet payload sentences) but is efficient overall.

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 tool with 3 parameters and an output schema, the description covers purpose, prerequisites, coordinate system, and one param's role. It lacks details on return values (output schema presumably covers that) and error cases. The sheet param missing is a gap, but overall it provides sufficient context for typical use.

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 coverage is 0%, so description must compensate. It explains 'pts' as polyline points and 'condition' as committing as a linear shape. However, 'sheet' is not described at all (likely an ID or key). This leaves one of three parameters unexplained, which is a gap given zero schema help.

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 measures an open polyline's length in linear feet at the sheet's scale, contrasting with siblings like measure_polygon (likely area). The verb 'Measure' and specific resource 'open polyline' make the action 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?

It specifies a prerequisite ('Requires the scale to be set') and mentions passing a condition to commit as a linear shape. Though it doesn't explicitly list alternatives, the sibling context (e.g., measure_polygon for closed shapes, set_scale for scale) provides implicit guidance. Could be more directive about when not to use.

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