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

Beyond the annotations, it discloses that this mutates a live account, that the result is created PAUSED by default, and that a confirm gate applies — real safety context. Slight tension: it says 'Created PAUSED' while the status param also accepts ENABLED, so the true default behavior is a bit ambiguous.

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?

One tightly packed sentence-plus-bracket, with the safety warning front-loaded before the operational detail; nothing is wasted.

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?

Covers the essentials for a 9-parameter mutation tool with full schema coverage and no output schema: write risk, confirm gate, default status, and format. Only gap is what the call returns (ad id?), which an agent might want but can discover.

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 every parameter is already documented, including the pipe-separated format and length limits. The description repeats those constraints ('>=3 headlines <=30 chars', '>=2 descriptions <=90 chars') but adds no semantics beyond the schema — baseline 3.

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 ('Create a responsive search ad in an ad group') and names the concrete constraints, making it clearly distinct from google_ads_create_ad_group, google_ads_get_ad, and google_ads_list_ads.

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 '[WRITE — changes your live account]' prefix and 'Requires confirm:true' establish when this applies versus the read-only siblings (get_ad, list_ads). It does not, however, say prerequisites such as the ad group needing to exist or point to an alternative tool for other ad types.

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