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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds scope (only outbound clicks from artifacts to your site, not all traffic) and the default lookback window, but says nothing about result size limits, ordering, or aggregation.

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?

One sentence, front-loaded with the resource and the key scoping qualifier (clicked from your artifacts to your own website), with the time window trailing. Nothing is wasted.

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?

A simple read-only tool with one optional parameter and no output schema; the description conveys what data comes back (visitors and pages) and the time window. Only the return shape's granularity and any limits remain unstated, which is minor here.

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 coverage is 0%, so the description must carry the parameter — and it does, defining 'hours' as the lookback window with a stated default of 168. It stops short of giving an accepted range or units beyond hours.

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?

States a specific resource (readers who clicked from artifacts to your own website) and the content returned (pages they visited). It is more concrete than siblings like reader_activity, though it never explicitly contrasts itself with those tools.

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?

Use is implied — referral analytics — but there is no explicit when-to-use or when-not, and the very close siblings reader_activity and recent_activity are not mentioned as alternatives. The agent must infer the distinction.

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