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

Adds substantial context beyond annotations: missing items surface in `meta.missing` with specific id formats, NSFW content is not filtered, and the credit cost model is broken out per item type. These are exactly the non-obvious behaviors an agent needs before calling.

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-loads the batch capability, then return semantics, then cost. Dense but each sentence carries information; the cost breakdown is longer than ideal but operationally relevant.

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 does explain the failure surface (meta.missing) and the cost model. It could say more about the shape of returned post/comment objects, but for a batch getter the essential calling information is present.

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 accepted formats (ids, t3_/t1_ fullnames, URLs, permalinks) are already documented per-parameter. The description reinforces this with 'Accepts the links people actually paste' and the share-link refusal, but adds little beyond the schema.

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 (fetch) and precise resources with caps (up to 100 posts/comments, 100 communities) in one call. This clearly distinguishes it from single-item siblings like get_reddit_post or get_reddit_comments and from search_reddit.

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 phrase 'Current state of items you already know about... in one request instead of one per item' tells the agent this is a batch-hydration tool for known ids/links, which implicitly excludes discovery use cases handled by search_reddit. It stops short of explicitly naming the alternative tools.

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