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

No annotations are provided, so the description carries the full burden. It discloses that the report excludes advertiser PII and matches the money fields/legend of get_publisher_report, which adds valuable behavioral context. However, it does not explicitly state read-only semantics, authentication, or rate limits, but 'report' implies a safe read operation.

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?

A single sentence that packs in the tool's purpose, scope, and relation to another tool, without fluff. The [Sell] tag provides additional context and the sentence is front-loaded with the core functionality.

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?

The description references get_publisher_report for field details, which is helpful but requires the agent to know that tool. The schema fully documents parameters, and the description gives enough context for a report tool. However, the lack of an output schema means the agent must rely on the referenced tool for response structure.

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 coverage is 100% for all 7 parameters, so the baseline is 3. The description adds minimal extra meaning beyond the schema, such as the optional nature of campaign_id and the period enum, which are already present. The note that campaign_id 'must be on your placements' is a minor enhancement.

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 it provides a 'Publisher period breakdown by campaign on your placements' and distinguishes itself from sibling tools like get_publisher_report_by_placement via the 'by campaign' qualifier and reference to 'same money fields/legend as get_publisher_report'.

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 campaign-level publisher reporting with an optional campaign_id filter and notes the absence of advertiser PII. It gives clear context but does not explicitly mention alternatives or when-not-to-use, though the name and reference to get_publisher_report provide a clear use case.

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