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

Annotations already declare readOnlyHint=true, so the description need not re-disclose that. It adds valuable context: FREE, no credits charged, returns draft and affordability (1000 credits), and the required follow-up workflow. No contradiction with 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 description is a bit long but every sentence serves a purpose: scoping, cost, output, workflow, and prerequisites. It is front-loaded with the 'preview, free, nothing created' key facts. Slightly dense but well-structured.

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?

Given the tool's complexity (7 params, no output schema, safety-critical workflow), the description covers everything an agent needs: what it returns, the credit threshold, the explicit-consent and next-step requirement, and the prerequisite product_id. Nothing essential is missing.

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 covers all 7 parameters at 100%, so baseline is 3. The description adds meaning beyond the schema by telling how to fill campaign_message ('from what you know about the product') and that product_id must come from search_products. This extra guidance raises it above 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?

Clearly states it previews a campaign before launch, returns a draft and affordability check, and explicitly says it does not launch. Distinguished from sibling create_content_campaign by the 'BEFORE launching' and 'never launch' emphasis.

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?

Explicitly instructs to call create_content_campaign after getting an explicit yes, and never launch off the preview alone. Also specifies that product_id must come from search_products and how to write campaign_message.

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