save_prefab

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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it does so excellently. It explains the technical limitation, clarifies that the tool returns the owning prefab path, and explicitly states it will not report a false success. This is exactly the kind of honest, non-obvious behavior an agent needs to know.

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 includes necessary behavioral caveats. The middle sentence contains fairly deep API internals (PrefabPublicRequestBus, SaveTemplateToString) that may be more detail than an agent needs, but it does justify why the tool behaves as it does. Overall it is well-structured with no fluff.

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 tool's unusual behavior, an output schema exists, and only one parameter is required, the description covers the essential selection and invocation context. The main gap is the under-explained entity_id parameter, but the agent can still reasonably infer it refers to the prefab instance whose origin should be reported.

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 must compensate for the undocumented entity_id parameter. It only implicitly suggests that entity_id identifies the prefab instance whose origin should be reported, but it doesn't explain the expected format, whether it is a persistent ID, or how it relates to other entity IDs in sibling tools. The compensation is minimal.

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 opens with a clear verb and resource: 'Report where a prefab instance came from.' It immediately distinguishes itself from the misleading name 'save_prefab' and explicitly names the sibling alternative create_prefab_from_entity, leaving no ambiguity about its actual behavior.

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 explicitly states when to use this tool and when not to: it cannot propagate live edits to a .prefab file, and it directs the agent to use create_prefab_from_entity when the goal is writing a prefab to disk. This is direct, unambiguous routing guidance.

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