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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds useful behavior beyond that: the return is JSON with the template in a 'template' field (compensating for the missing output schema), and it discloses that product/niche are written into the template and that omitting product leaves a placeholder.

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?

Front-loaded with the core purpose and return shape, then parameter semantics. It is slightly redundant where it re-explains the 'kind' enum already documented in the schema, but every sentence still carries useful information.

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, the description steps in and describes the return payload (JSON with the 'template' field). Combined with full parameter coverage and clear kind semantics, an agent has everything needed to call this correctly.

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 100%, so the baseline is 3; the description goes further by explaining the effect of 'product' (written into the template) and the fallback placeholder when it is absent, plus distinguishing the two 'kind' behaviors. It adds real semantic value over the enum and field descriptions.

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 states a specific verb and resource: it returns a prompt template built from one ad, for the user to run on their own product. It also spells out the two output variants (kind='swipe' vs kind='analysis') in concrete terms, so an agent can distinguish this from siblings like get_ad or advertiser_hooks without opening the schema.

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 description explains what each kind produces and notes the template is meant for the user's own product, which implies when to reach for it. However, it never names an alternative sibling or states when NOT to use this tool (e.g., use get_ad for the raw ad, advertiser_hooks for hooks), leaving routing to inference.

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