Visits Summary

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the agent knows this is a safe, closed read operation. The description adds value by disclosing the exact aggregate metrics returned, which is especially helpful since no output schema is provided.

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 two concise sentences: the first compactly lists the metrics, and the second gives the canonical use case. It avoids repeating schema details and has no filler.

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?

For a simple read-only summary tool, the description plus a fully described four-parameter schema is sufficient for an agent to select and invoke it correctly. The listed metrics compensate for the absent output schema, and the schema also covers site_id discovery via matomo_list_sites.

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 each parameter already carries a good description including date syntax, period enum, segment syntax, and site_id lookup guidance. The tool description adds little parameter-level meaning beyond framing the metrics around a site and period, so it stays at the baseline.

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 says this tool returns key traffic metrics for a site and period, listing visits, unique visitors, actions, bounce rate, actions per visit, and average visit duration. It is unmistakably the traffic-summary tool and is differentiated from more specialized siblings like matomo_pages or matomo_referrers.

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 phrase "The go-to tool for 'how much traffic did we get?'" provides a clear, memorable use case for when to select this tool. It does not explicitly enumerate when to avoid it or name alternative tools, but the guidance is strong enough for typical traffic-summary questions.

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