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

With no annotations, the description carries the burden and does well: it discloses the campaign is created PAUSED as a draft, requires manual activation on the Ads page, and depends on the ads add-on plus a connected account. These are real behavioral facts beyond the schema; it omits only edge cases and error 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?

A single sentence plus one compact caveat clause, front-loaded with the core action and no wasted words. Everything an agent needs at a glance is in the first half.

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 13-parameter mutation tool with no annotations and no output schema, the description covers the essentials: what is created, its state, prerequisites, and that the customer activates it. Return values are unspecified, but the omission is minor for a creation tool.

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 77%, so most parameters are already documented. The description adds little per-parameter meaning and slightly misaligns with the schema: it says 'phrase-match keywords' and 'Search only', while the schema exposes EXACT/PHRASE/BROAD match types and a PERFORMANCE_MAX/DISPLAY advertisingChannelType enum.

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?

Specific verb+resource: it creates a paused Search campaign with an RSA and phrase-match keywords, which cleanly separates it from google_ads_manage_campaign and list_ad_campaigns. The title says 'Search / Performance Max' while the description says 'Search only', a minor internal inconsistency that slightly muddies scope.

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 preconditions: needs the Google Ads add-on and a connected account, and it writes to the customer's own account as a draft they later activate. It does not explicitly name sibling alternatives (e.g. manage_campaign for edits), but the context is unambiguous.

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