Renew scene thumbnail

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

Annotations already establish idempotentHint=true and destructiveHint=false. The description adds useful behavioral context by explaining that Foundry does not automatically refresh the sidebar thumbnail and that this tool is the way to force it.

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 short sentences, with the core action first and the reason immediately after. Every sentence contributes; no filler or schema repetition.

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-parameter, idempotent, non-destructive operation with no output schema, the description covers what, why, and when. Nothing needed to call it correctly 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 already documents sceneIdentifier fully with 100% coverage, so the description does not need to repeat parameter details. It adds no parameter-specific semantics, matching the baseline for well-covered schemas.

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 says exactly what the tool does — 'Create the thumbnail of a scene anew' — and anchors it to a recognizable use case (background swap). This clearly separates it from scene-update or scene-read operations such as get-scene-image.

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 a concrete trigger: needed after a background swap because Foundry keeps showing the old picture in the sidebar. It does not explicitly enumerate alternatives or exclusions, but the intended context is unambiguous.

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