get_pmax_performance

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

Description goes beyond annotations by detailing API limitations (MIXED catch-all, unavailable channel splits), return structure (two result sets), and insights (weak ad strength, zero-conversion groups). Consistent with readOnlyHint and destructiveHint.

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?

Description is concise with front-loaded purpose. It uses line breaks for clarity but could be better structured with bullet points. Every sentence adds value.

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 output schema exists, description adequately covers result sets, metrics, insights, and date conventions. Lacks full parameter explanations but is otherwise complete for a read-only 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 coverage is 0%, description partially compensates by specifying date format 'YYYY-MM-DD' and default 'last 30 days'. However, customer_id parameter is not described, leaving ambiguity about its expected value.

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?

Description clearly states the tool gets Performance Max campaign and asset group performance, and distinguishes from siblings like get_campaign_performance by specifically targeting PMax entities. It lists two result sets and key metrics, making the purpose 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?

Description implies usage for PMax campaign performance but lacks explicit when-to-use vs alternatives. No mention of when not to use or comparison with sibling tools like get_campaign_performance, though the focus on PMax provides some guidance.

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