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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds the context of 'no auth, no state changes, no charges,' which goes beyond annotations by covering authentication and cost implications. This useful context does not contradict annotations.

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 sentence that front-loads the core purpose, then efficiently includes usage guidance and safety traits. Every phrase adds value, with no redundant or unnecessary language.

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 one optional parameter, an output schema, and strong annotations, the description provides sufficient context: what the tool returns, when to use it, and its safety profile. No critical information is missing for an agent to use it correctly.

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 input schema already describes the 'operation' parameter with a 100% description coverage, listing example operation IDs. The tool description does not add further parameter semantics, so a baseline of 3 is appropriate per the schema coverage rule.

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 clearly states 'Return public docs for Cannon Studio developer API operations and payload shapes,' specifying both the verb and resource. It also distinguishes from siblings by naming estimate_generation_cost and create_generation_request as tools to use after consulting this one.

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?

Explicitly advises to 'use this before estimate_generation_cost or create_generation_request when operation/input fields are unclear,' providing a clear when-to-use context. The safety note ('no auth, no state changes, no charges') also implies it is safe to consult as a first step.

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