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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true) by disclosing that the call is non-mutating until confirmed, that enabling a new ad triggers Reddit policy review (PENDING_APPROVAL), and that warnings can be returned for statuses like REJECTED or PENDING_BILLING_INFO. This is exactly the kind of side-effect and edge-case context an agent needs.

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 verb, resource and the PREVIEW qualifier, followed by tightly ordered sentences on side effects, return shape, and the confirm step. The trailing API docs link and some parenthetical detail add minor length but no real waste.

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?

For a three-parameter draft tool with an output schema, this covers everything needed: the draft/confirm contract, the policy-review consequence, warning semantics, and where the entity IDs come from. Nothing required to invoke it correctly 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 description coverage is 100%, and the schema already documents entity_id (with source read tools), entity_type values, and ad_account_id default behavior. The description adds no parameter-level syntax or format detail beyond that, so the baseline of 3 applies.

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 (enable), the resource (a Reddit campaign, ad group or ad), and the crucial scope qualifier that this is a PREVIEW that only drafts the change. It is immediately distinguishable from pause_reddit_entity, remove_reddit_entity, and the Google-side enable_entity sibling.

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?

Explains the two-step workflow clearly: this drafts, and nothing changes until confirm_and_apply applies the plan_id. It also notes the policy-review side effect for new ads. It does not explicitly state when to prefer this over alternatives, but the draft-vs-apply routing is spelled out.

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