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

Annotations declare the safety profile (destructiveHint=false, openWorld=true) but not the dry-run default; the description adds that the tool previews unless confirm is true and never unlinks, which is genuinely new context. It still doesn't describe rate limits, permission requirements, or what a preview response contains.

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?

Three compact sentences: what it does, the prerequisite, then the safety/mode behavior front-loaded where the agent needs it before calling. No filler.

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 mutation-style tool with annotations covering the safety hints, the description supplies the missing prerequisite and dry-run semantics. Absent an output schema it doesn't say what the preview or success result looks like, and it omits ads_personalization entirely.

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 75% and the confirm parameter is fully documented in the schema, so the description's restatement of preview behavior is largely redundant. The ads_personalization parameter has no schema description and the tool description ignores it entirely, leaving a real gap.

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 (Link) and both resources (Google Ads account, GA4 property) plus the downstream benefit (key events and audiences flow into Ads). 'Never unlinks' implicitly separates it from an unlink operation and the read-side sibling ga4_list_google_ads_links, so an agent can place it precisely.

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 a clear prerequisite ('Both must be linked to the same client here') and a mode condition ('Previews unless confirm is true'), which tells the agent when the call is safe versus committing. It stops short of naming the alternative tools (e.g., ga4_list_google_ads_links to check existing links) or stating when not to link.

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