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

Since no annotations are provided, the description carries the full burden. It discloses the tool is free, fetches remote URLs, unpacks zips (using first printable model), and warns about base64 truncation in the parameter notes. This is strong transparency for a read-only analysis tool, though it doesn't explicitly state no destructive actions, that's implied by 'sanity check'.

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 dense but well-structured: front-loaded with core purpose, followed by outputs, then input methods, and a sibling reference. Every sentence adds value, though it is somewhat long. It earns high marks for efficient communication.

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 complexity (multiple input methods, zip handling, heuristics, relationship to other tools), the description covers all important aspects: what it does, what inputs it accepts, how to handle local files, and when to use it relative to siblings. It doesn't detail the return schema, but the output items are listed and there is no output schema to rely on.

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 coverage is 100%, so baseline is 3. The description enriches parameter semantics beyond the schema by explaining accepted URL formats (Thingiverse, GitHub, Drive, direct links, zip), the zip 'first printable' behavior, and the upload fallback. The base64 truncation warning also adds operational context not present in the schema.

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 states a specific verb+resource: 'FREE geometry sanity check for an STL/3MF/OBJ/PLY model' and enumerates concrete outputs (bounding box, volume, triangle count, watertight flag, fits-on-bed, heuristics). It explicitly differentiates from sibling tools by pointing to analyze_3d_model for a general framing and to get_print_quote as a following step.

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?

Provides clear usage context: 'Great pre-flight before get_print_quote' and explicitly contrasts with analyze_3d_model. It also gives practical input guidance (URL types, zip behavior, upload workflow) that helps an agent decide when and how to invoke this tool.

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