list_campaigns

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds value by specifying what fields are returned (campaign name, status, budget, and performance metrics) and that it works across multiple platforms, but doesn't disclose pagination behavior, rate limits, or authentication requirements beyond what annotations provide.

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 perfectly concise with two sentences that each earn their place: the first states the core purpose, and the second specifies what data is returned. No wasted words, and information is front-loaded with the main functionality stated first.

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?

For a read-only list operation with good annotations and full schema coverage, the description is reasonably complete. It specifies the scope (all campaigns across platforms) and return fields. The main gap is lack of output schema, but the description compensates by listing return fields. Could be more complete with pagination or ordering details.

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?

With 100% schema description coverage, the schema fully documents all three parameters with descriptions and enums. The description mentions filtering by platform and returns performance metrics, but doesn't add meaningful semantic context beyond what's already in the structured schema. Baseline 3 is appropriate when schema does the heavy lifting.

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 verb ('List') and resource ('all campaigns across connected ad platforms'), specifying the scope as 'all campaigns' across multiple platforms. It distinguishes from sibling tools like 'get_daily_spend' or 'get_performance' by focusing on campaign listing rather than performance metrics or spend data.

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 usage for retrieving campaign information but provides no explicit guidance on when to use this tool versus alternatives like 'list_ad_accounts' or performance-focused tools. It mentions filtering by platform and status in the schema but doesn't explain when those filters should be applied versus using other tools.

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