get_viewport_screenshot

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

Without annotations, the description must disclose behavioral traits. It mentions returning an Image but does not specify if the operation is read-only, whether it requires an active viewport, or any side effects. It also lacks details like performance impact or error conditions. The transparency is minimal beyond the obvious.

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 very concise, with only two sentences: one for purpose and one listing the parameter. It is front-loaded with the main action and organized clearly. Every sentence is necessary and no extraneous information is present.

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 low complexity (single parameter, no output schema), the description is mostly adequate but missing some important context. It does not specify what 'Image' means (e.g., data URL, binary, path), nor does it mention that the screenshot is of the 3D viewport only (not UI elements). These gaps 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?

The only parameter, max_size, is described as 'Maximum size in pixels for the largest dimension (default: 800)'. This adds meaning beyond the input schema, which only declares type and default. The description clarifies that it applies to the largest dimension, helping the agent understand the scaling behavior.

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 clearly states the tool captures a screenshot of the current Blender 3D viewport. It uses a specific verb ('Capture') and resource ('screenshot of the current Blender 3D viewport'), which distinguishes it from all sibling tools that deal with downloading assets, executing code, or getting scene info.

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 no guidance on when to use this tool versus alternatives. It does not mention any prerequisites, limitations, or contexts where another tool might be more appropriate. For example, it could note that this is for visual inspection while get_scene_info is for data.

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