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

Annotations already declare readOnlyHint=true, destructiveHint=false and idempotentHint=true, so the safety profile is structured data; the description reinforces it ("Changes nothing in the ad account") and adds the operationally important note that per-operation parameters must be fetched via get_tool_schema. It still omits pagination, rate limits, auth requirements, and return shapes, which is why it isn't a 5.

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?

The read-only framing and the get_tool_schema pointer are front-loaded where they matter, but the bulk of the text is a comma-separated list of 23 operation names that exactly duplicates the schema enum, adding length without adding meaning. Every operation is named; none is explained.

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 23-operation dispatcher with an undocumented open `params` object and no output schema, the description covers only the safety stance and where to find parameter docs. It says nothing about what any operation returns or how to pick between related operations (e.g. get_structure vs get_ad_details vs get_breakdowns), so an agent must make an extra get_tool_schema round-trip for every call.

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 0% and `params` is an untyped free-form object with no documentation at all. The description's only guidance is "Parameters of an operation: get_tool_schema", which defers the semantics to a second tool call rather than explaining them — a useful pointer, but it leaves the agent unable to populate `params` from this definition alone. The enum values are self-descriptive, which keeps this above a 1.

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 resource and mode ("Google Ads, read-only operations") and enumerates the 23 supported operations, so an agent knows exactly what capability surface this tool covers. It does not explicitly contrast itself with google_ads_changes or the cross-platform get_performance, but the 'read' framing makes the line reasonably clear.

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?

Usage is only implied: 'read-only operations' plus the operation list tells the agent this is for pulling Google Ads data, and "Changes nothing in the ad account" hints that mutations belong elsewhere. There is no explicit when-to-use guidance, no statement that writes require propose_change/approve_change, and no help choosing among the 23 operations.

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