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

Annotations already establish read-only and non-destructive behavior, so the bar is lower. The description adds useful behavioral context: small rows are filtered out and comparison is against the preceding period. It doesn't explain exactly how the 'previous period' is defined, but this is a reasonable disclosure beyond the annotations.

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 short, front-loaded sentences with no filler. The core concept comes first and the example question follows. Every word earns its place, and the description is appropriately sized for the tool's complexity.

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 schema covers all parameters, but there is no output schema and the description does not describe what rows are returned or how the previous period is determined. For a tool with seven parameters and sibling comparisons, a bit more context about output shape or period boundary logic would strengthen completeness. It is adequate but has clear gaps.

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%, so every parameter is documented. The description does not add any parameter-specific detail beyond what the schema already provides. A baseline score of 3 is appropriate because the schema carries the full semantic load.

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 communicates the core function: comparing the current period with the previous one and surfacing gains/losses. The example question 'what dropped in the last 28 days' gives a concrete entry point. It doesn't use a strong verb+resource phrasing and doesn't explicitly differentiate from siblings like find_opportunities or top, but the comparison concept is distinct enough.

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 usage through the example question, indicating it is for change-analysis questions like 'what dropped'. However, it provides no explicit guidance on when to prefer this over alternatives, no exclusions, and no mention of sibling tools or conditions that would make another tool a better fit.

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