mne_plot_source_estimate

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

With no annotations, the description carries the transparency burden. It discloses the rendering dependency, that the estimate is still computed if rendering fails, and suggests mne_run_code for inspection. It doesn't mention side effects like whether the PNG is saved to a file, but it adds meaningful behavioral context beyond the name and 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 two sentences, front-loaded with the main action, followed by parameter hints and a prerequisite. Every sentence adds value, with no filler or redundancy.

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?

Given the tool's complexity (requires 3D rendering, has 3 parameters), the description covers purpose, a key parameter, and a failure fallback. But it omits details about the output PNG (where it goes), the meaning of 'stc_name', and any side effects, so for an agent to invoke it correctly, additional assumptions may be needed.

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?

The schema has no property descriptions (0% coverage), so the description must compensate. It explains the allowed values for 'hemi' ('both'/'lh'/'rh') and clarifies that 'time' defaults to peak time when null. However, 'stc_name' is not explained, leaving it ambiguous.

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 states the tool renders a source estimate as a cortical activation map (PNG) at peak time or given time, which is a specific verb+resource+output. It clearly distinguishes from sibling plotting tools (e.g., mne_plot_raw, mne_plot_evoked) by focusing on stc source estimates.

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?

It provides context for when to use: it requires PyVista off-screen rendering and offers a fallback to mne_run_code when 3D rendering is unavailable. However, it doesn't explicitly name alternative plotting tools or state when not to use it, so it falls short of a full when/when-not guide.

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