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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description contributes nothing beyond that: it does not explain whether results are paginated, what 'limit' defaults to, how dismissed recommendations are treated, or whether the listing reflects live or cached data.

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 front-loaded sentence with no filler, which is structurally clean. For a tool with five parameters and a filtering surface, however, this is under-specification rather than effective conciseness.

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 read-only list tool with no output schema and 20% parameter coverage, the description should at minimum explain the filters and result shape. As written it leaves an agent without enough context to invoke the tool correctly beyond the required customer_id.

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 description coverage is only 20% (customer_id is the sole documented parameter), yet the description mentions no other parameter semantics. Filters such as recommendation_type, include_dismissed, and limit are left completely unexplained in both schema and description, so the description fails to compensate for the coverage 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 (List), resource (Google Ads recommendations) and scope (for one customer). It does not, however, differentiate itself from the sibling read/mutate cluster (recommendation_apply_prepare, recommendation_dismiss_prepare), so an agent gets the 'what' but not the 'vs what'.

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?

There is no statement of when to use this tool, no prerequisites, and no reference to the apply/dismiss siblings that clearly consume its output. Usage is only inferable from the tool name cluster.

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