ap_material_update

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

With no annotations, the description carries the full burden and exceeds it: it warns 'THIS DOES NOT CHANGE THE VIEWPORT,' explains the render pipeline (layer stack vs. node graph source), and even provides measured evidence that viewport captures are byte-identical before and after. This is exactly the kind of non-obvious behavior an agent needs.

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 front-loaded with the core purpose and the critical viewport caveat, then gives concise alternatives and a call cadence. Every sentence contributes distinct, actionable information; the measured byte-identical detail is somewhat verbose but directly supports the transparency claim.

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 zero-parameter tool with no output schema and no annotations, the description is complete: it explains what the tool does, when to call it, what it will not do, and how to achieve the visible result the user wants. No critical guidance is missing.

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 input schema has zero parameters and 100% coverage, so there is nothing for the description to add about parameter meaning. The 0-parameter baseline is 4, and the description appropriately focuses on call semantics instead of inventing parameter details.

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 verb and resource: 'Recompile the active material after node edits.' It also immediately clarifies that the tool does not change the viewport, which distinguishes it from paint/fill tools and other material operations like ap_material_create or ap_material_delete.

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 explicit when-to-use guidance: 'Call this once after a batch of ap_node_* edits.' It also names alternatives for making edits visible (ap_fill_layer, ap_paint_stroke, ap_paint_stroke_world), so the agent knows exactly how to route its next action.

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