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

Beyond the readOnlyHint annotation, the description adds that the response includes a `definitions` field explaining metric counting, which helps the agent interpret returned values. It does not address rate limits or auth, but the read-only nature is disclosed.

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 sentences with the primary function front-loaded; 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?

The tool is a simple read-only query with only two parameters; the schema documents both, and the description enumerates the metrics plus the definitions field. This is sufficient for an agent to invoke it correctly.

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?

Both parameters have full descriptions in the schema (100% coverage), so the description adds no additional parameter meaning. The tool description references 'site and range' but the schema already defines them.

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 specifies a concrete resource (a site and date range) and a clear verb ('get overview') with an explicit list of KPIs (visitors, pageviews, orders, etc.), making it distinct from siblings like get_live or get_funnel which focus on narrower scopes.

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?

It says 'Headline KPIs for a site and range' which clarifies the intended use case as high-level metric retrieval. It doesn't explicitly discuss when not to use it, but the sibling context plus the metric list makes appropriate usage clear.

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