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

With readOnlyHint=true and openWorldHint=true already declared, the description adds valuable context: values are normalized relative interest (0-100 within the result set), not absolute search volume. This goes beyond annotations and helps the agent interpret results correctly, though it does not cover return format or rate limits.

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?

Three sentences, front-loaded with the core action, and every sentence adds value—what it does, when to use it, and how to interpret results. No filler or repetition of schema details.

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 tool's complexity (5 parameters, no output schema), the description adequately covers the essential semantics: temporal scope, comparison behavior, and normalization. It could mention the return format (e.g., time series of points), but the normalization and comparison details largely compensate for the lack of an output schema.

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 100%, so the baseline is 3. The description enhances parameter understanding by explaining that multiple keywords are compared on one scale and that results are relative, not absolute. This adds interpretive meaning that the schema's field descriptions do not fully convey.

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 uses a specific verb ('Get') and resource ('relative search interest over a historical period'), clearly distinguishing it from siblings like get_interest_by_region (geographic) and get_related_queries (related terms). It also clarifies the comparative aspect ('passing multiple keywords compares them on one scale'), which sets expectations precisely.

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?

Explicit when-to-use guidance is provided ('Use this when the user asks how popular something is, whether it is rising or falling, or how several things compare'). It does not mention when not to use it or name alternative tools, but the context is clear enough for an agent to select this tool appropriately.

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