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

With no annotations, the description carries the full behavioral burden. 'File discarded' is a useful side-effect disclosure, but the description omits what the tool actually does with each parameter, whether it returns a count directly or wraps it, what errors occur, and how it handles the schema's 'no disk access' constraint.

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 extremely short with no filler or repetition, and it front-loads the core operation. It is a fragment rather than a complete sentence, but the terseness itself is not the main problem; the missing content is penalized elsewhere.

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?

This is a 10-parameter tool with no annotations and no output schema, so the description needs to explain which input to provide and what the return value looks like. It does neither: it only gestures at a vertex count and file disposal, leaving the invocation contract almost entirely unspecified.

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 100%, so each parameter is already documented in the schema. The tool description adds no parameter-level meaning and does not indicate which parameter, if any, represents the Wavefront OBJ input, so the baseline of 3 is appropriate.

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 names a specific operation and resource: counting vertices in a Wavefront OBJ file and discarding the file. However, it never connects that operation to the tool's 10 input parameters, none of which obviously carries an OBJ file, so an agent cannot tell what to pass in.

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?

There is no guidance about when to choose this tool over the many sibling shape/check tools, nor any context about prerequisites or exclusions. The OBJ mention implies a narrow use case, but that implication is not developed into actionable guidance.

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