set_material

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

No annotations are provided, so the description carries the disclosure burden. It clearly communicates the core mutation (assign material and density) and the response behavior (updated mass in kg), which is useful. However, it does not mention side effects such as whether existing materials are overwritten, whether changes are persistent, or any permission requirements.

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 a single well-structured sentence with no filler. It front-loads the action and efficiently adds unit and output information that is not present in the schema.

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 mutating tool with no annotations and no output schema, the description is too thin. It lacks preconditions (e.g., whether a model must be open or document_id must reference a part), a return structure beyond mass, and error or edge-case context. It is minimally usable but not complete.

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. It adds meaning for density_g_cm3 by specifying units (g/cm³) and relates the output to mass in kg, but it does not explain what document_id refers to or what values name expects.

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 uses a clear action verb ('Assign') with a specific resource ('part material and physical density') and states the resulting output ('report updated mass in kg'). It is unambiguous about what the tool does, though it does not explicitly differentiate it from sibling tools like update_feature or set_entity_state.

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?

No when-to-use or when-not-to-use guidance is provided, and no alternatives are mentioned. The description only defines the operation itself; an agent has to infer when this tool is appropriate relative to sibling mutation tools.

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