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

Annotations already flag a non-read-only, non-idempotent, open-world operation, but the description adds real value beyond them: it discloses that the call consumes a scarce 'analysis allowance' and that the output is a creative hypothesis rather than proof of profitability. That quota-consumption and expectation-setting context is exactly what annotations cannot convey.

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 tight sentences with zero filler, and the leading clause carries the core action while the trailing clause handles the caveat. Nothing is repeated from structured 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?

Because an output schema exists, return values need not be described, and the hypothesis-vs-proof caveat covers the key output caveat. However, with 0% schema coverage and no usage routing, the definition is only minimally complete for a side-effectful, quota-consuming operation.

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 0%, with three required parameters (brandId, adId, idempotencyKey) and no property descriptions. The description alludes to 'a selected public ad' but never explains the required ids or the role of idempotencyKey, so it 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 (Analyze) and resource (a selected public ad), so an agent can tell it apart from read-only siblings like get_library_ad or search_library_ads. It stops short of naming those alternatives, but the analysis framing is 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?

The phrase 'using the existing analysis allowance' implies a quota-gated operation, which is useful context, but there is no explicit when-to-use vs. when-not, and no pointer to get_library_ad, get_ad_breakdown, or compare_intelligence as alternative paths. Guidance is left to inference.

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