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

Annotations already declare readOnly, idempotent, closed-world reads, so the safety profile is covered. The description adds a genuine domain constraint the agent could not otherwise know: Google only supplies monthly granularity, and the tool defaults to the newest month with data. It omits retention window or how many months back data exists.

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, front-loaded with what the tool returns, followed by the key constraint and default. No filler or repetition of the tool name.

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 three params, no nested objects, and no output schema, the description covers the essential facts: what is returned, the granularity limit, and the default period. The only gap is the absence of any hint about response shape or ordering, which is minor for a simple list-returning read.

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 67%: limit and month are documented in the schema, while profile_id carries only a uuid format. The description reinforces the monthly granularity of the month parameter conceptually but adds no syntax or format detail beyond the schema's YYYY-MM pattern, so the baseline 3 applies.

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 names the concrete resource (search terms people used to find the profile on Google) and its scope (one month of data), which is clearly distinct from siblings like get_performance_insights or list_reviews. It stops short of explicitly differentiating itself from adjacent analytics tools, but the resource is unambiguous.

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?

It tells the agent the default behavior (newest month with data), which is useful, but gives no guidance on when to prefer this tool over get_performance_insights or other analytics siblings, and no exclusions or prerequisites. Usage is implied by the resource name only.

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