Screenshot the figure

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

readOnlyHint=true already tells the agent this is a safe read; the description usefully adds that the result is a PNG of the drawing area and that full_window pulls in the algebra panel. It does not mention image size, resolution, or whether the capture reflects current zoom/state, so remaining behavioral gaps are minor but real.

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 tight sentences, front-loaded with the return type and immediately followed by the parameter explanation. No filler or restated boilerplate.

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 single-boolean, read-only capture tool with no output schema, the description covers what is returned and what the flag does. Only the absence of any note about image dimensions or capture fidelity keeps it from being fully complete.

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 carries the load, and it does explain the one parameter clearly: full_window captures the whole GeoGebra window including the algebra panel, versus the default drawing-area-only view. This is meaningful semantics beyond the bare boolean and default in the schema.

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: 'Return a PNG image of the drawing area.' The parenthetical use cases (overlapping labels, off-screen figure, wrong shape) sharpen it further. It does not distinguish itself from close siblings like ggb_snapshot or ggb_export, which prevents a 5.

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?

Gives clear context for when to reach for it: visual verification of the figure. However, it offers no guidance on when to prefer ggb_snapshot or ggb_export instead, and no exclusions, so it sits below the explicit-alternatives tier.

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