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

Going well beyond the annotations, it discloses latency ('about 20-40 s'), cost ('Uses 1 carousel from the user's plan'), and the return payload (slide URLs, per-slide layers, preview image). The credit consumption in particular is critical behavioral context for a non-read-only, non-idempotent operation.

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?

Three dense sentences, front-loaded with the core action, then cost/latency, then return shape. No filler and nothing repeated from the 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 generation tool with no output schema, it covers the three things an agent most needs before calling: what it produces, what it costs (plan credit), and how long it takes, plus a pointer to edit_carousel for the returned layers. Nothing essential is missing.

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%, with defaults, enums, and cross-references to list_options documented per property, so the schema does the heavy lifting. The description adds no parameter-level detail beyond naming the topic concept, which meets the baseline but no more.

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?

It states a specific verb and resource ('Create a finished carousel from a topic in one step') and enumerates the internal pipeline (idea, slides, photos, render), so the agent knows exactly what it produces. It does not explicitly distinguish itself from the sibling build_carousel, which is the closest candidate for confusion.

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?

Implicit usage context is clear: topic-in, finished carousel-out, and it points to edit_carousel for follow-up edits. However, it names no alternative for when a different path (build_carousel, create_carousel_from_video, supplying your own photos) should be chosen, leaving the agent to infer from the parameter names.

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