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

Annotations already convey readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it guarantees 'Returns the metadata and thumbnail for each item in the same order as the supplied asset_ids,' which informs the caller about output ordering. This is a meaningful behavioral trait not implied by the schema or annotations.

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 compact yet comprehensive. It opens with the core purpose, then the usage context, then exclusions, and finally the return behavior. Each sentence earns its place without redundancy, making it easy for an agent to parse quickly.

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?

Without an output schema, the description must delineate the return value. It states the tool returns metadata and thumbnails and preserves input order, which covers essentials. While it does not enumerate each metadata field in the response structure (e.g., exact JSON shape), it lists the fields in the opening sentence. Given the tool's read-only nature and the schema's thorough parameter descriptions, it is sufficiently complete for correct invocation.

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 schema already provides detailed descriptions for both parameters. 'asset_ids' includes guidance on usage ('When checking which media is the target on a page, include every image and video ID from that page'), and 'user_intent' is clearly mandatory. The description adds little beyond the schema, so a baseline score of 3 is appropriate.

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 explicitly states the resource (images and videos in a Canva design) and the exact fields returned (names, tags, types, creation dates, thumbnails). It also differentiates from siblings by stating it is 'Not for design metadata or editing the media itself,' making it distinct from get-design-content and perform-editing-operations.

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 provides clear usage context: 'Use when you need to check which image or video is the target on a page, look up its details, or preview it before changing it.' It also gives exclusions: 'Not for design metadata or editing the media itself.' However, it does not explicitly name alternative tool names (e.g., get-design-content or perform-editing-operations), so the guidance is strong but not fully explicit about alternatives.

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