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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely new behavior: it costs nothing and makes no Meta API call, which materially affects tool selection. It omits any statement about batch limits or latency, but that is a minor gap against the annotation coverage.

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 tightly packed sentences, front-loaded with the return contract and finishing with the two facts that most influence selection (no Meta call, no cost). 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?

With no output schema present, the description correctly compensates by listing the returned fields, so an agent knows the response shape. It does not mention the 10-name cap or ordering, though the schema covers the cap.

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 100% and the single parameter carries its own example (["pause_ad","update_budget"]), so the schema does the heavy lifting. "For each named operation" mildly confirms batch semantics that match the array type, but adds no syntax beyond the schema.

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 explicitly enumerates what is returned per operation (full input schema, description, spend, metered, reversible, router), which is a concrete resource definition an agent can act on. It does not, however, distinguish this tool from the sibling search_tools, which likely overlaps in intent, and the verb itself is only implied by the name.

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?

"For each named operation" implies the calling pattern (pass operation names), and "Free. Does not call Meta." gives a practical incentive to prefer this over live-API siblings. There is no explicit when-to-use/when-not statement and no routing against search_tools, so usage is only implied.

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