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

Annotations already declare idempotentHint=true and openWorldHint=true, so the idempotency and safety profile are partly covered. The description adds genuine value beyond them by disclosing credit cost ("Each successful file costs one credit") and the reuse-only-for-same-request rule, but says nothing about failure/partial-batch behavior or how pages map to the output.

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 short sentences, front-loaded with the core action, each carrying a distinct fact (purpose, cost, idempotency). Zero filler.

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 6-parameter mutation tool with a nested data object, one undocumented enum, no output schema, and 17% schema coverage, the description is too thin. It omits how pages/data are used and what a successful or failed call returns, so an agent lacks enough to invoke it confidently.

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 only 17% — only idempotency_key is documented in the schema — so the description must carry the burden for template_id, format, pages, data, and version. It implies a saved template is required but explains none of the other five parameters, their constraints, or the nested data object.

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 ("Create ordered image pages from one saved template"), which conveys the carousel concept clearly. It does not name sibling alternatives like create_image_pack or create_batch, so it lacks explicit differentiation, but the purpose is unambiguous.

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?

There is no statement of when to use this tool versus the many sibling creation tools (create_batch, create_image_pack, create_ai_image). The idempotency sentence is parameter guidance rather than when-to-use context, leaving selection to inference.

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