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

Annotations are all default-false (readOnlyHint=false, openWorldHint=false, destructiveHint=false), so they convey no meaningful behavioral profile. The description adds one useful behavioral hint — 'Position, width, and height use sensible defaults' — implying the tool auto-handles layout settings. However, it does not disclose what happens on success, error conditions, or the embed_type/link_url dependency.

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 short sentences with the core action front-loaded and the default-behavior note deferred to the second sentence. There is no filler or redundancy; every word 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?

The description covers the essential purpose and the auto-default behavior, and the presence of an output schema covers return values. However, it leaves the embed_type/link_url relationship implicit and offers no guidance on distinguishing embed widgets from the many sibling widget-add tools, which is a meaningful gap given the large sibling set.

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 baseline is 3. The description adds nothing beyond the schema, which already documents all five parameters, including the embed_type enum and the conditional note on link_url for URL/IFRAME modes. The description does not compensate for any schema gap, but none exists.

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 states the verb 'add,' the resource 'embed widget,' and the target 'a page,' clearly identifying the core operation. It distinguishes itself from sibling add_button_widget/add_image_widget/add_text_widget tools by widget type, though the differentiation relies mostly on the name 'embed' rather than a stated contrast.

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?

No when-to-use guidance is provided. There is no mention of when to choose this over sibling add_*_widget tools, nor when update_embed_widget would be the appropriate alternative. The conditional relationship between embed_type and link_url (link_url only for URL/IFRAME modes) is left for the agent to infer from the schema.

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