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

Annotations already declare the operation as read-only, idempotent, and non-destructive. The description adds value by enumerating the exact KPIs returned, which clarifies what data the tool exposes. It doesn't mention any additional behavioral nuances, but none are needed given the simple, safe nature of the tool.

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 a single, compact sentence that front-loads the verb and resource, then efficiently lists the KPIs. Every word adds value, with no redundancy or 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 zero-parameter read-only tool with an output schema, this description is complete. It specifies all the key metrics returned, and the presence of an output schema covers structural details. There are no missing caveats or prerequisites that would be expected.

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?

The tool takes zero parameters, so the baseline score is 4. The description doesn't need to explain parameters; it lists the output metrics, which is the primary semantic content here. No additional parameter guidance is required.

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 clearly identifies the tool's purpose with a specific verb ('Get') and resource ('high-level business KPIs'), followed by a concrete list of metrics. This distinguishes it from sibling stats tools like get_booking_stats or get_invoice_stats, which focus on narrower domains.

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 conveys clear context: this is for overall business KPIs, not domain-specific stats. However, it doesn't explicitly state when to use it over alternatives or provide exclusions, so it falls short of a full 5.

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