Draft a Reddit ad

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

The description discloses significant behavior beyond the annotations: it creates a profile post and a paused preview ad, verifies click_url reachability, explains that Reddit ad comments are public, and details the post_id path where headline/body/image are ignored and profile_id defaults to the post's. This is consistent with readOnlyHint=false and destructiveHint=false and provides rich behavioral 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?

The description is dense but front-loaded with the main action and then efficiently explains modes, constraints, and defaults. It is appropriately sized for a tool with 13 parameters and two distinct workflows, though a brief list or section separation could make it slightly easier to scan.

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 13 parameters, 0% schema coverage, and the presence of an output schema, the description covers the most important creation modes, verification behavior, comment defaults, and post_id semantics. It is slightly incomplete because it does not explain the required ad_group_id/ad_account_id relationship or what display_url means, but it is otherwise close to sufficient.

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%, so the description must carry parameter semantics, and it does for most key parameters: profile_id, post_type, headline, body, image_url, click_url, call_to_action, allow_comments, and post_id. However, some parameters like ad_group_id, ad_account_id, display_url, and ad_name receive no semantic explanation, leaving a noticeable 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?

The description opens with a specific action and resource: 'Draft a Reddit ad: creates a post on the profile, then the ad (PAUSED) — PREVIEW.' It also distinguishes itself by covering two modes — creating a new post or promoting an existing post via post_id — so it is clearly separate from sibling tools like draft_reddit_campaign, draft_reddit_ad_group, or update_reddit_ad.

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 gives useful context about how to use the tool, such as sourcing profile_id from list_reddit_funding_instruments and using post_id for existing posts, but it never explicitly states when to prefer this tool over alternatives or when not to use it. With many reddit-related sibling tools present, the usage guidance is implied rather than explicit.

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