get_campaign_performance

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

Annotations already mark the tool as readOnlyHint=true and destructiveHint=false. The description adds value by disclosing the returned metrics (impressions, clicks, etc.), date format requirements, and that empty date defaults to last 30 days. This provides behavioral context beyond the 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 extremely concise: two sentences and a list. The first sentence states the purpose, followed by a clear list of returned fields and format notes. No superfluous words.

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 3 parameters and an output schema, the description covers the date range semantics and return fields. However, it omits an explanation of the customer_id parameter, which is a minor gap. Additional details about pagination or result aggregation would be helpful but not critical.

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 has 0% description coverage, so the description carries the full burden. It explains the date parameters (format and default behavior), but does not explain the customer_id parameter. This addresses 2 of 3 parameters, adding significant 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?

The description clearly states 'Get campaign-level performance metrics for a date range,' specifying the verb (Get), resource (campaign-level performance metrics), and scope (date range). It distinguishes from sibling tools like get_keyword_performance and get_ad_performance by focusing on the campaign level.

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 implicitly indicates when to use this tool (when campaign-level metrics are needed) but provides no explicit guidance on when not to use it or alternatives. The sibling tool names imply alternatives, but the description does not mention them directly.

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