get_aggregate

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

No annotations are provided, so the description carries the full burden. It states the tool returns aggregated metrics per site per period, implying a read-only query. However, it does not disclose potential edge cases (e.g., missing data, rate limits, or whether it's safe to call repeatedly). More details on non-destructive nature or data scope would have improved transparency.

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 sentences, highly concise. The first sentence front-loads the output and site constraint. The second provides a usage template. No unnecessary words, earning its place efficiently.

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?

With no output schema, the description should hint at the return format. It lists metrics but not their structure or data types. The schema covers parameters well. The description is adequate for a simple aggregate tool but could be improved by noting the output shape (e.g., a JSON object with those keys).

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 100%—both parameters have detailed descriptions in the schema. The tool description adds no new parameter-specific information beyond what the schema already says. Baseline 3 is appropriate since the description meets but does not exceed the schema's guidance.

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 states the tool returns 'period totals for one site' with specific metrics (visitors, pageviews, bounce_rate, visit_duration). It provides a concrete usage example, making the purpose unambiguous. While sibling tools like get_timeseries and get_breakdown exist, the description's focus on aggregate totals and the example naturally differentiate it.

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 suggests using this tool for 'how many visitors did site X get in date range Y' style questions, providing clear context. However, it does not mention when to avoid this tool or list alternatives explicitly, which would make it a 5.

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