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

Annotations already declare this is a non-readonly, non-destructive, non-idempotent, closed-world write. The description adds meaningful context beyond that: a 20–40 s runtime expectation and that it consumes 1 carousel credit — both operationally relevant for an agent deciding whether to call it and how to handle latency.

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?

Two sentences, zero filler, with the core action front-loaded and the cost/latency caveat trailing. Every clause earns its place.

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 an 11-parameter generative tool with a fully documented schema and no output schema, the description covers origin, output shape (slides + photos + render), latency, and quota. The one gap is that it never says what identifier or handle comes back, which matters if the agent needs to poll get_carousel or edit_carousel afterward.

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%, so every one of the 11 parameters (theme, layout, strategy, slides, fonts, images/photo_ids, mix_stock, hook_style) is already documented in the schema, including defaults and cross-references to list_options. The description adds no parameter semantics of its own, so baseline 3 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 and resource ('Turn an idea ... into a finished carousel') and names the upstream producer (generate_ideas), so the agent knows an idea_id must come from there. It does not, however, distinguish itself from the sibling create_carousel, which an agent could easily confuse with 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?

The prerequisite ('an idea from generate_ideas') and cost ('uses 1 carousel') are stated, which implies when this tool is appropriate. But there is no explicit when-not guidance and no mention of when to prefer create_carousel or create_carousel_from_video instead.

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