google_ads_campaign_performance

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

With no annotations provided, the description carries full burden. It clearly indicates a read-only operation ('Get metrics') but lacks details on authentication, rate limits, or what happens on error. As a read tool, it is adequate but not comprehensive.

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 fairly concise with a clear intro and structured Args section. It could be slightly tighter, but the format is helpful and not verbose.

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 that an output schema exists, the description does not need to explain return values. All parameters are documented, and the tool's purpose is clear. However, it lacks context on error handling or edge cases, which keeps it from a 5.

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?

Despite 0% schema description coverage, the description includes an Args section that explains each parameter in detail, including format for customer_id, predefined date_range options, campaign_status as list, min_cost as number, limit range, and response_format choices. This adds significant meaning beyond the schema.

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 clearly states the tool's function: 'Get comprehensive performance metrics for campaigns.' The verb 'Get' and resource 'performance metrics for campaigns' are specific and distinct from sibling tools like google_ads_account_performance or google_ads_campaign_comparison.

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 description implies the tool is for retrieving campaign performance but does not explicitly state when to use it over alternatives or provide exclusions. The sibling list exists but no differentiation is given.

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