results_render

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

No annotations are provided, so the description carries full behavioral disclosure. It discloses that the image is returned inline, saved next to the input file unless image_path is given, that vector variables default to magnitude or can pick a component, that warping scales by warp_factor, and that crop_bounds clips before framing the camera. This is rich operational detail beyond the schema.

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?

The description is dense but every sentence adds value: output format, dependency, coloring, warping, camera, crop bounds rationale, and output file behavior. It is front-loaded with the core purpose and does not repeat schema information verbatim.

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 10-parameter tool with no annotations and no output schema, the description covers most behavior thoroughly, including the critical crop_bounds use case. However, it omits show_edges and window_size details and does not explicitly discuss return values or potential failure modes, leaving some gaps.

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?

With 0% schema description coverage, the description compensates well for many parameters: file type, variable, component, warp_by (via DISPLACEMENT example), warp_factor, camera presets, crop_bounds format, and image_path. However, it does not explain show_edges or window_size behavior, leaving those parameters underdocumented.

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 opens with a specific verb+resource+output: 'Render a VTK/VTU result file to a PNG screenshot'. This clearly distinguishes results_render from sibling tools like results_list, results_probe, results_summary, and results_animate, all of which have different purposes (listing, probing, summarizing, animating).

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 description gives useful usage context: it warns about the optional 'pyvista' extra, explains variable coloring, warping, camera presets, and highlights crop_bounds as essential for small bodies in huge domains. However, it does not explicitly state when NOT to use this tool or name an alternative like results_animate for motion visualization.

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