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

The description adds useful behavioral context by noting that position, width, and height use sensible defaults, which is beyond the schema. However, it does not explain the creation side effect, required references, or any other behavioral nuance; annotations are minimal but consistent.

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 a concise two-sentence definition with no redundant text. The main purpose is stated first, and the useful defaulting behavior is added in the second sentence without wasting words.

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?

Given a fully described schema and an output schema, the description is nearly complete for invoking the tool correctly. The main gap is the absence of usage guidance relative to sibling tools, but this is partially covered by the tool name and schema.

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 the input schema fully documents each parameter. The description itself adds no parameter-level meaning beyond the schema, so the 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 clearly states a specific action and resource: 'Add an image widget to a page.' This distinguishes it from other sibling add_*_widget tools by naming the widget type and target without ambiguity.

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 gives no guidance on when to use this tool versus alternatives such as add_asset_to_page, add_embed_widget, or update_image_widget. It does not mention prerequisites or exclusions; usage is only implied by the tool name.

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