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

The description goes beyond annotations by explicitly stating 'Public read-only: no auth, no state changes, no charges.' This adds valuable context about access control, side-effect freedom, and cost, which is highly relevant for agent decision-making. It aligns with the readOnlyHint and destructiveHint annotations without contradiction.

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, information-dense sentence that front-loads the action and resource, lists key categories, and includes crucial safety/behavioral notes. No wasted words or redundancy.

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?

The description is largely complete for a read-only list tool with no required parameters. It explains the purpose, routing nuances, and safety profile. However, it does not explicitly compare with sibling listing tools or describe output structure, though the presence of an output schema mitigates the latter. Overall, it covers the essential context well.

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 provides complete descriptions for all four parameters (action, family, media_type, project_context_only), and the description does not add additional parameter-level semantics. Since schema coverage is 100%, the baseline of 3 is appropriate; the description's focus is on output characteristics rather than parameter guidance.

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 the tool's function: listing specific categories of Cannon Studio toolkit surfaces (image, video, audio, etc.) and highlighting API vs. app/Director Mode routing. This specific verb+resource scope distinguishes it from sibling tools like list_capabilities and list_offerings.

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?

The description provides clear context on what information the tool returns (which toolkits are API operations vs. app/Director Mode), which signals when to use it. However, it does not explicitly mention alternatives or when not to use it, so it misses the highest bar of explicit exclusions.

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