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

Beyond the readOnlyHint and destructiveHint annotations, the description adds valuable behavioral context: one-call-per-page, dependence on an editing transaction, and the non-negotiable instruction to show every thumbnail preview to the user. No contradiction with annotations exists.

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 front-loaded with the core purpose and keeps the needed operational details in a compact sequence. The all-caps emphasis is redundant in wording but serves a real functional purpose, so the length remains justified.

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 covers the prerequisite workflow, the one-page-per-call constraint, and the required user-facing display behavior. It does not describe the exact response payload, but the absence of an output schema is mitigated by the clear instruction to show the returned thumbnail preview.

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 already provides full descriptions for transaction_id and page_index, including the one-based indexing rule and the exact source of the transaction ID. The description mostly restates these requirements without adding deeper semantic meaning beyond what the schema already provides.

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 resource and action: getting the thumbnail for a specific page of a design within an editing transaction. It distinguishes this from sibling tools like get-design-pages or get-design by focusing specifically on thumbnail retrieval tied to a transaction ID and page index.

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 specifies the prerequisite of using start-editing-transaction to get the transaction ID, and clearly states that each call retrieves one page's thumbnail. It does not name alternatives or exclusions, but the context is unambiguous and actionable.

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