compare_periods

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

Without annotations, the description discloses return values (aggregates, change, percent change) and that periods are arbitrary. But it omits potential edge cases like data gaps or metric availability.

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?

Single sentence, 20 words, front-loaded with action and result. No redundancy.

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?

Given nested objects and no output schema, the description explains return values but lacks detail on metric constraints and output structure. Sibling tools are not referenced for differentiation.

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 description adds minimal meaning beyond the input schema: it names 'metric' and 'arbitrary date periods' but does not clarify possible metric values or period constraints. Schema covers format for start/end only.

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 compares a metric between two date periods and returns aggregates with change. However, it does not differentiate from sibling tools like get_trends or get_health_metrics.

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 implies use for comparison but provides no guidance on when to use this tool versus alternatives, nor any conditions or prerequisites.

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