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

Annotations already declare destructive, open-world, non-idempotent behavior. The description adds valuable context: negatives suppress ad serving across every ad group, and it explains match-type semantics including the default BROAD behavior.

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 short paragraphs, front-loaded with what the tool does and its behavioral effect, followed by when to use it. Every sentence adds useful information without repetition.

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?

Complete enough for a destructive live-campaign mutation: it covers the effect, default match behavior, and a candidate-finding workflow. Minor gaps remain around when not to use it and duplicate/return behavior, but the core call context is present.

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%, so the schema already documents the parameters. The description adds meaningful defaults and enum behavior: matchType defaults to BROAD, and per-keyword PHRASE or EXACT can override it.

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: add campaign-level negative keywords to a live Google Ads campaign. It also clarifies scope by noting suppression across every ad group, which distinguishes campaign-level negatives from ad-group-level controls.

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?

Explicitly says when to use it: when reports show wasted spend on irrelevant queries, and it points to the keyword performance section of get_campaign_report. It does not state when not to use it or name alternatives such as remove_keywords.

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