get_campaign_performance

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not state that the tool is read-only, mention any permissions or rate limits, or explain what happens if no data is available. The 'get' prefix implies a read operation, but this is not explicit.

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 a single concise phrase listing the key metrics, with no redundant wording. It is front-loaded with the core purpose. However, it is so brief that it borders on under-specification, though the conciseness itself is not flawed.

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 the tool has only one parameter and no output schema, the description is incomplete. It does not explain the parameter, does not state read-only behavior, and does not specify any constraints like date ranges or filtering. An agent has limited ability to call it correctly without additional schema inspection or guessing.

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?

The schema defines a single parameter 'days' with a default of 30, but the description provides zero explanatory value for it. With schema description coverage at 0%, the description must compensate, yet it does not mention that 'days' controls the lookback period or any format/details. An agent is left to guess what this parameter means.

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 identifies the tool as retrieving campaign performance metrics, listing specific metrics (impressions, clicks, spend, conversions, CPA). This is a specific verb–resource combination, but it does not explicitly differentiate itself from sibling tools like get_ad_performance or run_report, so it stops short of a 5.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention that it only operates on campaigns, nor does it suggest run_report for custom reporting or other performance tools for ad/keyword level data. The usage context is entirely implied by the name and description.

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