vfx_upload

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

With no annotations provided, the description carries the full behavioral burden and does so well: it discloses that uploads are public, moderated and permanent, that they require an explicit request, that they run under the Studio user's account, and that duplicate uploads are suppressed unless force is true. This is unusually complete for a mutation tool with no annotation coverage.

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?

Three compact sentences, front-loaded with the core action and followed by the critical safety and idempotency constraints. No sentence is wasted.

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 permanent, public mutation tool with no annotations and no output schema, the description covers the important ground: auth context, moderation, permanence, when to use it, and duplicate handling. The main remaining gap is fuller explanation of the bake parameter, which is only indirectly described.

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 only 33%, so the description must compensate. It adds meaningful semantics for force (bypasses the duplicate-upload check and returns a new id) and implicitly ties bake to the baked PNG, but it does not explain the bake parameter's format or how studio_id is used beyond the schema's own note.

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: uploads a baked PNG via Roblox's Studio MCP and records the asset id in the recipe. That clearly distinguishes it from siblings such as vfx_bake (which produces the PNG) and vfx_render/vfx_preview (which do not publish assets).

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?

It gives explicit usage conditions: "only on an explicit request, after the look is settled." That tells the agent when to invoke it and implies when not to, though it does not name a specific alternative tool for other cases.

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