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

Annotations already cover the safety profile (readOnlyHint=false, destructive=false, non-idempotent), and the description goes further with real behavioral constraints: single-use link, 24-hour expiry, 500 MB cap, accepted formats (STL, 3MF, zip), and automatic simplification of large models for pricing. It stops short of stating failure/expiry behavior or what happens if a link is regenerated, so a 4 rather than a 5.

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?

Dense but waste-free: purpose first, then the workflow routing, then the file/expiry constraints. Every sentence carries an actionable fact; nothing restates the title or 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 zero-parameter, non-destructive creation tool with an output schema present, the description supplies everything an agent needs to decide to call it and what to do afterwards (surface upload_url, await confirmation, then call get_print_quote with upload_id). Return-value detail is correctly left to the output schema.

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 tool takes zero parameters and the description correctly implies as much, describing the trigger conditions (file present, contents unpassable) rather than any arguments. With no parameters the schema-coverage question is moot, so the baseline 4 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?

States a specific verb+resource ('Create a one-time upload page for the user's model file') and immediately scopes it in contrast to a named sibling: it is for cases where the file exists on the user's side and 'you cannot pass its contents to get_print_quote'. An agent can distinguish it from get_print_quote without opening either schema.

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?

Explicit when-to-use ('when the user has the file attached in chat or on their device'), explicit routing to the alternative (get_print_quote) for the other case, and a clear hand-off instruction: give the user upload_url, then call get_print_quote with upload_id once they confirm upload. No inference required.

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