femm_plot_field

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 does disclose real behavioral facts: output is rendered from bulk mesh arrays, default artifact is <work_dir>/field_B.png, and save_arrays additionally writes nodes/elements/B as .npz. It omits error behavior when no solution is loaded, whether an existing file is overwritten, and any session/permission requirements.

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 dense sentences, front-loaded with what the tool produces and the headless guarantee, followed by parameter-level detail. No filler, though the parenthetical and clause stacking make it slightly hard to parse on first read.

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, the description does most of the necessary work for a 4-param plotting tool: it names the artifact, its default location, the zoom format, and the save_arrays side effect. Remaining gaps are the unexplained 'session' parameter and the unstated precondition that a solution must already be loaded/solved.

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 largely does: zoom is defined as [xmin, xmax, ymin, ymax] in problem units, path is tied to the default field_B.png output, and save_arrays is explained as writing nodes/elements/B arrays to .npz. The 'session' parameter (default 'main') is never mentioned, which is the only uncovered parameter.

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 ('|B| colour map of the loaded magnetics solution') and clarifies the mechanism ('rendered from the bulk mesh arrays, works headless, no GUI screenshot'). This implicitly separates it from the GUI-dependent siblings like femm_make_plot and femm_save_bitmap, though neither is named explicitly.

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 'works headless, no GUI screenshot' note implies the tool is for headless rendering contexts, which is useful routing context against plotting siblings. However, it never states when to prefer this over femm_make_plot/femm_save_bitmap, nor what prerequisite (a loaded/solved magnetics problem) must hold.

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