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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior. The description adds genuinely new context beyond that: synchronous execution, task support forbidden, and that the payload is internal orchestration state with presentation rules. It stops short of describing pagination or volume characteristics, but adds real value over the annotations.

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 purpose is front-loaded, but the remainder is a dense block of boilerplate response-formatting rules with a duplicated period and slight redundancy ('raw JSON, data, or meta'). It is readable but not tight; the presentation guidance crowds out actual tool semantics.

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?

An output schema exists, so return values need not be explained, and the annotations carry the safety profile. But with 15 parameters at 0% schema coverage and no parameter guidance in the description, the definition is materially incomplete for correctly invoking this read tool.

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?

The schema has 15 parameters with 0% description coverage, and the description mentions no parameter at all—not even the required advertiserId. With this many undocumented inputs, the description was the only place to compensate and it contributes nothing, so it fails badly here.

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 and resource ('Read saved advertiser creative opportunities and source provenance'), so the core action is clear. However, it does not differentiate from closely named siblings such as get_creative_intelligence_run, run_creative_intelligence, or create_creative_intelligence_plan, leaving an agent to infer which one to call.

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?

The only 'usage' guidance concerns response presentation (use assistantSummary first, don't display raw JSON) rather than when to select this tool versus alternatives. There is no statement of when-to-use, prerequisites, or which sibling to prefer, so tool-selection guidance is essentially absent.

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