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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral scope beyond the annotations: it returns structural fields only and intentionally excludes performance metrics. It doesn't discuss pagination or result volume, which is the remaining gap.

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?

Two sentences, no filler, and the scope constraint plus the alternative tool are front-loaded so the routing decision is made immediately.

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?

There is no output schema, so the enumeration of returned fields carries real weight and compensates well. It is nearly complete for a two-parameter read tool, lacking only minor details such as whether results are paginated or how removed campaigns appear.

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 description coverage is 100%, so both customerId and includeRemoved are already documented in the schema, including the important multi-account error behavior. The description mentions returned fields rather than parameters and adds no parameter syntax beyond the schema — baseline 3 is appropriate.

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?

States a specific verb+resource ('List campaigns for an account') and enumerates the returned structure (id, name, status, channel type, bidding strategy, daily budget). It also explicitly differentiates itself from the sibling get_campaign_performance, so an agent can route without opening either schema.

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?

Names the alternative tool (get_campaign_performance) and the exact condition that selects it ('for spend/results'), and clarifies the scope boundary of this tool ('Structure only (no performance metrics)'). This is explicit when-to-use/when-to-use-something-else guidance.

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