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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description adds value beyond that: it discloses the two-phase draft/confirm model, that a preview with a plan_id is returned showing old → new, and that no mutation occurs until confirm_and_apply. This is exactly the behavioral context an agent needs for a staging tool.

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 purpose, then the key constraint, then the confirm workflow — every paragraph earns its place. The trailing Reddit Ads API documentation URL is mildly extraneous but harmless as a reference.

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?

An output schema exists, yet the description still usefully characterizes the return (preview with plan_id). Combined with the workflow and editability constraints, an agent has everything needed to call this correctly in a multi-step Reddit ad update.

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%, so all five parameters are fully documented in the schema itself (including the TEXT-ad click_url caveat). The description restates name/click_url/comments but adds no syntax or format detail beyond the schema, so the baseline 3 for high coverage 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 and resource ('Draft changes to a Reddit ad') plus the editable field set (name, click_url, comments). It explicitly distinguishes itself from the sibling draft_reddit_ad by explaining that new copy requires a new ad, so an agent can route correctly without opening either 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?

Gives an explicit when-to-use-this-vs-alternative rule: editable fields go here, but headline/body edits require draft_reddit_ad plus pausing the old ad. It also states the follow-up requirement (nothing applies until confirm_and_apply), so the agent knows the full workflow.

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