creo_get_mass_properties

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the read-only safety profile is pre-covered. The description adds 'uses unit density for calculation only' as useful extra context, but 'does not modify the model' merely restates what the annotations already imply.

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 sentences convey the resource, scope, calculation caveat, and non-mutating behavior without filler. The key purpose is front-loaded, and every clause earns its place.

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 low-complexity read tool with one optional parameter and strong safety annotations, the description covers the main contextual needs: target selection, safe directory, unit-density caveat, and non-modification. It does not describe the return shape, but the absence of an output schema and the simple read semantics make this a minor gap.

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?

There is only one optional parameter and the schema description fully documents it: 'Optional part file name in the safe output directory. Omit to read the current model.' The tool description adds little beyond what the schema already provides, so the baseline 3 applies.

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 specific verb and resource: 'Read computed mass properties' for either the current Creo part or a part copy in the safe output directory. This distinguishes it from sibling query tools like creo_get_dimensions and creo_get_features, and from the many create_safe_* copy tools.

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 clearly states the two valid targets — the current model or a saved part copy in the safe output directory — so an agent knows when the tool applies. It does not explicitly name alternatives or when not to use it, but the context is clear enough for this simple read operation.

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