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

Goes well beyond the readOnly/idempotent annotations: it discloses the exclusion of REMOVED campaigns, the exclusion of today from the window, currency handling (major units), portfolio-strategy fallback behavior, sort order (cost descending), and cursor pagination semantics.

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?

Front-loads the scope and window before the metric list, and each sentence carries real information. The long enumeration of returned fields is dense but justified given there is no output schema.

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?

With no output schema, the description compensates by naming the returned fields, unit conventions (ctr 0-1, money in major units), and pagination behavior. Nothing essential for correct invocation is missing.

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 the schema already documents days, limit, cursor, status, and customer_id in detail. The description adds only marginal parameter notes (e.g., passing next_cursor back as cursor), so the baseline 3 applies.

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 and resource (lists campaigns in one account) and enumerates the returned settings and performance metrics. It is clearly distinguishable from siblings like get_campaign_setup and get_campaign_draft because it is the reporting-oriented listing tool.

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?

Gives clear usage context: last N complete days with today excluded, REMOVED campaigns never returned, and status filtering with ENABLED/PAUSED. It does not explicitly name an alternative sibling to use instead, so it falls short of a 5.

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