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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered structurally; 'nothing is applied' restates it with useful emphasis. Beyond that, nothing is disclosed about result volume, whether an empty list is the normal outcome, or how openWorld account resolution behaves, which matters for a tool whose scope is data-dependent.

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?

Two short sentences, front-loaded with the resource and its field payload, then the safety qualifier. Nothing is padded or repeated, and the parenthetical earns its space by previewing return fields.

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, zero-required-parameter retrieval tool with annotations and no output schema, the definition covers what is returned (type, campaign, estimated impact) and that nothing changes. The only real gap is default/limit behavior and what an empty result means, which is minor given the tool's simplicity.

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 67%: folder and account carry their own descriptions (including the folder-covers-all-accounts rule), so the schema does the heavy lifting there. The description adds no parameter meaning at all, and the one undocumented parameter (limit, with a 1-100 bound but no described default or effect) is left unexplained in both schema and description. Mid coverage with no compensating text lands at baseline.

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?

The description names a specific resource (Google's optimization recommendations) and scopes it to the account, then lists the payload fields (type, campaign, estimated impact). It does not name or differentiate against any of the many nearby google_ads_* siblings (e.g. policy_issues, query, pmax_insights), so an agent must infer the boundary itself.

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: nothing is applied' signals this is a retrieval step, but the description never says when to reach for recommendations versus adjacent diagnostic tools such as google_ads_policy_issues or google_ads_pmax_insights. No exclusions, no prerequisites, no follow-up routing.

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