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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read profile is covered. The description adds nothing beyond that – no mention of pagination behavior (despite an 'after' cursor), sort order, or what a comment record contains – so it contributes no behavioral context of its own.

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?

Three words carry no filler, but this is terseness rather than useful conciseness – there is no front-loaded scope or qualifier to anchor the agent. It is efficient but under-specified.

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 so return-value explanation is not required, but for a subreddit-scoped comment listing alongside several near-identical reddit siblings the definition leaves the critical routing information (which sibling fetches which comment set) entirely absent.

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%, with 'subreddit', 'limit', and the 'after' pagination cursor all documented in the schema. Per the baseline rule, a 3 applies when the schema does the heavy lifting and the description adds no parameter detail.

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 'Reddit subreddit comments.' merely restates the tool name rather than stating a verb+resource action. An agent learns that comments are involved but not whether this fetches, searches, or streams them, and it is indistinguishable from siblings like reddit_comments and reddit_user_comments.

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?

There is no indication of when to use this tool versus reddit_comments, reddit_subreddit_posts, or reddit_user_comments. No prerequisites, ordering, or selection criteria are given, leaving the agent to guess from the name alone.

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