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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds behavioral context beyond that: preset ids are validated server-side and a preset only works in its matching mode, which helps the agent understand the constraints around using the returned values. This is useful supplementary behavior information.

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 two concise sentences with the core purpose front-loaded. It avoids fluff and immediately gives the most actionable guidance: call before fattly_generate_ad. Every sentence adds value.

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 simple optional-parameter listing tool with no output schema, the description covers the key returned categories, the prerequisite relationship, and the matching-mode constraint. The mode semantics are already in the schema, so the overall context is complete.

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% and the single 'mode' parameter already has a detailed description explaining each enum value and the omit behavior. The tool description does not need to repeat this information, so the baseline score 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?

The description clearly states the tool lists Ad Studio offerings: ad presets (templateId), scenes, and creator avatars. It names a specific resource and differentiates itself from generation tools like fattly_generate_ad by framing itself as the prerequisite listing tool.

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 explicitly instructs calling this tool BEFORE fattly_generate_ad, which is critical for correct sequencing. It also warns that preset ids are validated server-side and only work in matching modes, giving clear practical context for when this tool is needed.

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