Explain a traffic change

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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds the important caveat that results describe association, not causation, which is valuable behavioral context 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 sentences, no filler, front-loaded with core action. Every sentence adds value.

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 the complexity (11 parameters, nested filters, multiple comparison modes) and low schema coverage, the description is too sparse. It covers high-level purpose but lacks guidance on required parameters, how to set comparison mode, and interpretation of results. The output schema is present but not described.

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 only 45%, and the tool has 11 parameters. The description adds no parameter-level information (e.g., no explanation of websiteId, start, end, comparisonStart, etc.). It only lists possible dimensions but not how to specify 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 clearly states the tool compares traffic across periods and ranks changes across specific dimensions (pages, referrers, countries, devices, channels, events). It distinguishes from sibling 'compare_traffic_series' by focusing on explaining changes rather than time series visualization.

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 mentions comparison modes (previous, year-over-year, custom) and dimensions, but does not explicitly state when to use this tool versus alternatives like compare_traffic_series or get_metrics. There is no guidance on when not to use it.

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