imgui_set_style_var

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

No annotations are provided, so the description carries the full burden. It doesn't disclose whether setting a style var temporarily or permanently changes state, whether it requires prior window setup, whether it automatically triggers a redraw, or whether particular var_name values are restricted to certain types. The persistence/scoping of the change is completely undocumented.

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, compact and to the point. The examples are useful without being excessive. Front-loaded with the core purpose first, then type breakdown. No wasted words.

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 2-param tool with full schema coverage and no output schema, this is reasonably complete. The main gaps are: no list of valid var_name values (only examples), unknown error behavior for unsupported names, and no mention of persistence or redraw behavior. But given the simplicity of the tool, it's minimally sufficient.

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 100% and both parameters are described. The description adds some value by clarifying that value can be a float OR a [x,y] array and lists valid var examples. However, it only names a handful of the many ImGui style variables, so the agent might be uncertain whether other unsupported names exist or would error.

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 it sets an ImGui style variable and distinguishes between float and vec2 variants with concrete examples. The verb+resource (set style var) is specific and the purpose is clear. However, it doesn't explicitly differentiate from sibling imgui_set_style or imgui_set_theme/theme_color, though the distinction is fairly obvious.

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 guidance on when to use this tool versus imgui_set_style, imgui_push_style_color, or imgui_set_theme_color. It doesn't mention whether this persists, whether it affects global or per-window state, or whether there are alternatives for color-based styling. The context of when to use a style variable over other styling tools is absent.

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