interest_by_region

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

With no annotations, the description carries the full behavioral burden and does disclose the important constraint matrix between resolution and geo, including the non-US REGION-only limitation. It says nothing about read-only nature, rate limits, pagination, or error behavior, so it is only partially transparent.

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 compact sentences with the core purpose front-loaded and no filler. The shorthand notation ('geo='' only') is dense but readable, and nothing is wasted.

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?

For a 7-parameter tool with 0% schema description coverage and no annotations, the description covers only the resolution/geo interaction. The return shape is arguably handled by the output schema, but the remaining call-critical parameters are left entirely unexplained.

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 0% across 7 parameters, so the description must compensate. It explains the semantics and valid values of resolution and its coupling to geo, but says nothing about keywords, timeframe, gprop, category, or limit, leaving most parameters undocumented anywhere.

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 phrase 'Where a keyword is searched most' states the resource and the breakdown dimension (geography) clearly, which separates it from the time-oriented sibling interest_over_time. It is not a clean verb+resource statement and no sibling is named explicitly, so it lands just short of a 5.

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 resolution/geo compatibility rules ('COUNTRY (geo='' only)', 'CITY and DMA ... geo='US' or worldwide only') effectively tell the caller when a given configuration is legal, which is real usage guidance. However, there is no guidance on when to choose this tool over interest_over_time or related_queries.

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