Create circles / ellipses

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

With readOnlyHint=false, destructiveHint=false, and idempotentHint=false already declared, the description still adds real behavior: placement is bound to the active window type, 3D windows reject 2D elements, results are returned per-item in input order, and one failing item does not abort the batch. It does not state permission/undo implications, but the partial-failure and window-constraint disclosures go meaningfully beyond the annotations.

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?

Front-loads what the tool draws, then the style fields, then the storage/return contract, so the most decision-relevant facts come first. It is dense and somewhat long, but nearly every clause (window constraint, default story, batch error semantics, follow-up tools) carries information.

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?

There is no output schema, yet the description spells out the return shape ([{guid, type} | {error}] in input order) and partial-failure semantics. Combined with the window/story placement rules and pointers to modify_elements and get_element_details, an agent has everything needed to call this correctly.

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%, so units (m, mm, degrees), defaults, and enumerated style fields such as pen, colorOverridePen, lineType, lineWeight, category, and zoneBoundary are already documented in the schema. The description restates a subset of these fields and adds units but no syntax or semantics the schema lacks, matching the baseline 3.

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 (draws full 2D circles / ellipses) and immediately disambiguates the geometry via the required parameters (center + radius, minorRadius/axisAngle for ellipses). It is easily separable from siblings like create_arcs, create_polylines, and create_elements without opening any schema.

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?

Gives concrete usage context: elements land in the ACTIVE window's database, the floor plan uses storyIndex (default current story), and a 3D window cannot hold 2D elements. It also routes the agent onward to modify_elements and get_element_details. It stops short of explicit sibling alternatives (e.g. when to prefer create_arcs), so it is clear context rather than full when/when-not routing.

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