Draw Circle

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is a non-destructive, non-idempotent mutation. The description usefully adds the unit convention (cm not mm, degrees), which is behaviorally relevant, but says nothing about what happens with no sketch present or how the new geometry affects downstream features.

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?

A single tight sentence with the action front-loaded and the unit caveat attached; nothing is wasted and no filler is present.

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?

With no output schema and no annotations covering return values, the description covers the essential unit semantics but omits error/failure behavior (e.g., no active sketch) and any note on whether defaults place the circle at the sketch origin. Adequate but with clear gaps for a state-mutating tool.

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 carry parameter meaning. It clarifies the unit system for lengths and coordinates (cm) and angles (degrees), which is genuinely useful, but never explains that center_x/y/z define the circle center or that they default to 0; the reader must infer this from the parameter names.

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 ('Draw a circle') and scopes the target ('in the most recent sketch'), which meaningfully narrows it among drawing siblings like draw_rectangle, draw_arc, and draw_line. It is clear but does not explicitly contrast with those siblings.

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?

No indication of when to use this versus draw_arc, draw_rectangle, or create_polygon, nor any prerequisite such as requiring an existing/active sketch. The mention of 'most recent sketch' implies context but gives no explicit condition.

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