Create Rectangle

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

Annotations already establish the safety profile (readOnlyHint=false, idempotentHint=false), so the description's burden is lighter. It adds genuinely useful behavioral context beyond annotations: the result is a single 'closed' polyline rather than four line segments or an open polyline, and it delegates to entity_create_polyline. However, it does not disclose effects on current drawing state, error conditions, or coordinate-system assumptions, leaving notable gaps.

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 sentences, no filler. The primary action and result shape are front-loaded, and the sibling-routing note earns its place in the second sentence. Every word contributes.

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?

Complete for a simple convenience wrapper: the schema documents all parameters with defaults, annotations cover mutation and non-idempotency, and an output schema exists so return values need no explanation. The wrapper note contextualizes behavior via entity_create_polyline. The only minor gap is that axis-alignment/current-UCS assumptions are implied but not explicitly stated, which is reasonably inferable from the two-corner-point geometry.

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 100% — all six parameters (x1, y1, x2, y2, color, layer) already have meaningful descriptions with defaults. The description's 'between two corner points' is consistent with the schema's 'First corner'/'Opposite corner' but adds no new parameter-level meaning. Baseline 3 applies since the schema does the heavy lifting.

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?

States a specific verb and resource: 'Create a closed rectangular polyline between two corner points.' The geometry is precisely defined (closed, rectangular, between two corners), and the wrapper note names entity_create_polyline, distinguishing it from the many other entity_create_* siblings without needing their schemas.

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 phrase 'Convenience wrapper around entity_create_polyline' gives clear context that this is the specialized path for rectangles, implicitly telling the agent to use this instead of hand-building a polyline with entity_create_polyline. It provides a clear usage context but does not explicitly state when-not-to-use or enumerate alternatives like entity_create_line or entity_create_circle.

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