interest_over_time

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

Annotations already declare readOnly/idempotent/openWorld safety, lowering the bar, yet the description adds real behavioral context: result granularity scales with timeframe (minute/hour up to ~9 months daily, 5 years weekly, longer monthly) and long series are averaged down to the requested points. That is substantive detail an agent cannot get from 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?

Front-loaded with the one-line purpose, then a clean per-parameter list. It is dense but each line maps to an otherwise undescribed parameter, so little is wasted given the 0% schema coverage; only minor tightening is possible.

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 six optional parameters, an output schema present, and no schema descriptions, the definition still documents every input, the default-location behavior, and the resolution/averaging semantics. Nothing an agent needs to invoke it correctly is missing.

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 0%, so the description carries the full burden and does so thoroughly: keyword operators ('a + b', 'a -b', '"a b"'), timeframe shorthand (1h...all, 6m/2y/45d, year, month, explicit date pairs), geo, category, property enum values, and the meaning of points=0. Every one of the six parameters is explained.

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 opening sentence states a specific verb, resource and scope: 'Search interest over time for up to 5 terms on one shared scale — the main Google Trends chart.' This is unambiguous and hints at primacy among siblings, but it never names an alternative (compare_periods, trend_details, keyword_overview) to sharpen the distinction.

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?

Usage is implied through dense parameter guidance and useful pointers to helper tools (find_topic, find_location, find_category), which tell the agent how to construct a call. However, there is no explicit when-to-use vs. when-not guidance against the many overlapping siblings that also return trend data.

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