get_account_performance_summary

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the daily granularity and account-level scope but does not disclose what performance metrics are returned, how data is aggregated, or timezone/currency conventions. No contradiction with 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?

The description is short and front-loaded, with the core purpose stated in the first sentence. The Args block provides necessary parameter context without unnecessary filler.

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?

The tool is simple with 2 parameters and read-only annotations, so the basic call surface is understandable. However, there is no output schema, and the description leaves ambiguous what 'performance summary' includes, what predefined date ranges are allowed, and how results are structured. These gaps matter for a reporting tool.

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 burden of parameter meaning. It does clarify date_range by showing 'YYYY-MM-DD,YYYY-MM-DD' and mentioning predefined values, but it does not enumerate the accepted predefined values. customer_id is minimally explained as 'Google Ads customer ID', adding little beyond the schema title.

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') with a clear resource ('account-level daily performance summary'). The 'account-level' scope distinguishes it from sibling tools like get_campaign_performance and get_ad_group_performance.

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 phrase 'account-level daily performance summary' provides clear context for when this tool is appropriate versus campaign-, ad-group-, or keyword-level reporting tools. It does not explicitly list exclusions or alternatives, but the scoping is strong enough to guide selection.

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