add_circle

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

With no annotations, the description carries the full behavioral burden yet only documents argument meanings. It does not state that this mutates board state, whether the change is undoable/revertable, or what the return value indicates. The mm units are the one genuinely useful behavioral detail.

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 purpose sentence followed by a tight parameter list; no filler. Front-loaded purpose statement, every line earns its place given the zero schema coverage.

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?

An output schema exists, so return values need not be described. For a board-mutating tool with no annotations, however, the definition should mention that it modifies the document and whether an open board is required; that gap keeps it at minimum-viable.

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 compensate, and it does: all six parameters are explained with units for the geometric ones. It omits the defaults encoded in the schema (layer=F.SilkS, width_mm=0.15, filled=false), which limits it slightly below a 5.

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 ('Add a graphic circle'), which is enough for an agent to distinguish it from siblings like add_rectangle, add_arc, and add_polygon. No explicit sibling differentiation in the text, but the resource noun is 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?

There is no guidance on when to use this versus add_rectangle, add_arc, or add_polygon, nor any prerequisite context (e.g., that a board/document must be open). Usage must be entirely inferred from the tool name.

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