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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds valuable behavioral context: which interaction types are included (chat, search, navigation, form submission), that results are ranked by occurrence count, and that this reports the origin page rather than destination. This goes beyond what annotations provide.

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 sentences, each earning its place: what the tool returns, how it differs from a key sibling, and when to use it. The most important distinguishing information is front-loaded.

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 is complete for this tool: annotations cover the read-only safety profile, the schema fully documents both parameters, an output schema exists, and the description provides the key conceptual distinction from get_top_clicked_urls. Nothing needed for correct selection or invocation is missing.

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 both parameters (limit and time_filter) are already fully documented in the schema. The description adds no parameter-specific semantics beyond confirming the ordering by occurrence count, which aligns with limit's 'ordered by count descending.' The baseline of 3 is appropriate because the schema does the heavy lifting.

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 a specific verb and resource ('Page URLs the user was ON when they interacted with the embed') and clearly defines the ranking criterion ('ranked by occurrence count'). It also directly differentiates itself from get_top_clicked_urls by clarifying origin vs destination, so an agent can distinguish them without opening schemas.

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 contrasts with get_top_clicked_urls and states the intended use case: 'Use this to find which pages of the host site drive the most embed engagement.' This gives clear when-to-use guidance and names the relevant alternative.

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