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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint=false, so "Read-only: returns public data and changes nothing" largely restates structured data. The credit-per-request cost note is genuinely useful context not present in annotations, but the description says nothing about pagination behavior or result limits despite exposing a cursor parameter.

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 short front-loaded sentences with no waste, and the core verb+resource leads. The middle sentence slightly duplicates what the annotations already declare, keeping it from a 5.

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?

Adequate for a simple search tool with full schema coverage and rich annotations, but incomplete for a paging-capable search: nothing explains result volume, cursor semantics, or how comment results differ from post results. The subreddit parameter's own note that it only applies to post search is left unaddressed by the description.

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?

Baseline is 3 given 100% schema coverage, but the description earns above that by flagging the cost per request, which affects how an agent should use the cursor and query broadly. Additionally, the schema itself carries rich enum and default documentation that the description need not repeat.

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+resource ("Search Reddit comments") that clearly distinguishes it from reddit_get_comment (single comment fetch) and reddit_list_subreddit_comments (enumeration). However, it does not explicitly name any sibling as an alternative, so differentiation is inferred from names alone.

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 offers no when-to-use guidance, no exclusions, and no routing to alternatives such as reddit_search_posts or reddit_search_all. An agent must infer from the tool name that this searches comment bodies rather than post titles.

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