get_keyword_performance_report

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds almost no behavioral context beyond those hints: it never says which metrics/columns come back, whether results are paginated beyond the limit cap, or how large result sets behave on an open-world Google Ads account.

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?

Purpose is front-loaded in a single line, followed by a compact Args block that maps one-to-one to the five parameters. No filler sentences, though the boilerplate Args formatting adds minor visual noise.

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 five parameters, no output schema, and no enums, the description documents inputs adequately but says nothing about the shape or content of the returned report. For a reporting tool with no output schema, an agent cannot predict the response columns or units from the definition alone.

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%, so the description must carry parameter meaning and largely does: it labels customer_id as the Google Ads customer ID, marks campaign_id and ad_group_id as optional filters, and gives date_range syntax ('YYYY-MM-DD,YYYY-MM-DD') plus the limit default of 100. Only the set of allowed predefined date-range values is left unspecified.

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?

States a specific verb and resource ('Get keyword-level performance metrics'), which is clearly a read of keyword metrics. It does not, however, distinguish itself from the near-identical sibling get_keyword_performance or from get_search_terms_report, leaving the agent to guess which is the right entry point.

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?

No explicit when-to-use or when-not-to-use section exists. Usage is only implied by the optional campaign_id/ad_group_id filters, which suggest narrowing a keyword report, and by the date_range parameter, which suggests time-bounded reporting.

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