mmar_get_scene_instance

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

No annotations are provided, so the description carries the burden. It discloses what the tool returns (the complete SceneInstance with nested parts), but it does not explicitly state read-only nature, session/auth requirements, or error behavior. Since it's a read operation, the risk is lower, but the disclosure is limited to return content.

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 two sentences, front-loaded with the primary action ('Get the full details...') and followed by a concise list of return contents. No redundant or filler language.

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 simple one-parameter getter with no output schema, the description adequately explains both the purpose and the return structure. It specifies the type of instance and the included sub-instances, making it complete for the tool's scope.

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 schema already provides 100% coverage for the uuid parameter with a description. The tool description adds no additional meaning beyond 'by its UUID,' which is already implied. Baseline of 3 is appropriate since schema does the heavy lifting.

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's function: 'Get the full details of a specific model instance (diagram) by its UUID.' It uses a specific verb and resource, and the second sentence enumerates the returned components (class instances, relationclass instances, etc.), which distinguishes it from sibling getters and listers.

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 implies the usage scenario: when you need full details of a specific scene instance by its UUID. It gives clear context (specific instance, full details) but does not explicitly state when not to use it or name alternatives such as mmar_list_scene_instances. This fits 'clear context, no exclusions.'

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