Mne Plot Source Estimate

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

With no annotations, the description carries the full burden. It discloses the rendering requirement and the graceful degradation when 3D rendering is unavailable, noting that the estimate is still computed and can be inspected via mne_run_code. It also specifies the output type (PNG) and timing behavior. It doesn't explicitly state side effects (e.g., read-only nature), but the plotting nature is implied.

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 with no filler. The core purpose is front-loaded, and the prerequisite/fallback information is included without bloat. Every sentence earns its place.

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?

The description covers the main behavior, hemisphere options, timing, and the PyVista dependency. However, it omits the meaning of stc_name and does not detail the output format (though an output schema exists). For a tool with no annotations and sparse schema, the missing stc_name semantics leave a gap that could confuse an agent.

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 0%, so the description must compensate. It explains the hemi parameter values ('both' / 'lh' / 'rh') and the time parameter's meaning (peak time or given time), but does not clarify the stc_name parameter (likely the workspace variable name). This partial coverage leaves one of three parameters undocumented.

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 a specific action ('Render') and a specific resource ('source estimate (stc)') as a 'cortical activation map (PNG)', and it specifies the timing (peak or given time) and hemisphere options. It clearly distinguishes itself from sibling plotting tools that target epochs, raw, evoked, or ICA data.

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 provides context on when to use it (for source estimates) and mentions a prerequisite (PyVista off-screen rendering) plus a fallback (mne_run_code). However, it does not explicitly state when NOT to use it or name alternative tools for similar tasks (e.g., mne_plot_topomap for topographic maps), leaving some routing to inference.

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