Reddit MCP Server

get_post_flairs

Read-only

Retrieve a subreddit's selectable post flairs with IDs to use when creating a post. Requires Reddit credentials; some subreddits restrict flairs to members.

Instructions

List a subreddit's selectable link flairs (flair text + flair_id) for use with create_post. Read-only, but requires user credentials; many subreddits expose flairs only to members, so this can 403 or return empty anonymously. Pass a returned flair_id (and flair_text for text-editable flairs) to create_post. For the subreddit's posting rules use get_subreddit_rules instead.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "subreddit_name": "<subreddit_name>"
    },
    "name": "get_post_flairs"
  }
}

Input Schema

Name	Required	Description	Default
`subreddit_name`	Yes	The subreddit name, without the r/ prefix (e.g. 'gadgets').

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.5.3Aug 20, 2026

TDQS

A4.7/5.0

Behavior5/5

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

Beyond the readOnlyHint annotation, the description discloses that user credentials are required, that anonymous access may 403 or return empty, and that many subreddits expose flairs only to members. This adds meaningful behavioral context not present in the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and well-structured: it states the purpose, adds important auth/behavioral caveats, explains how to use the output, and points to the alternative tool. Every sentence earns its place with no fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter list tool with no output schema, the description is complete: it explains what is returned, how to use it, when it may fail, and which sibling tool covers the related use case. The annotations and schema cover the remaining context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already fully documents the single parameter subreddit_name, including the r/ prefix guidance. The description does not add additional parameter-level meaning, so the baseline score of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool lists a subreddit's selectable link flairs, including the exact returned fields (flair text + flair_id). It also distinguishes itself from the sibling get_subreddit_rules by explicitly directing users there for posting rules.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly explains when to use this tool: to obtain flairs for create_post, and tells the user to pass the returned flair_id/flair_text to create_post. It also names get_subreddit_rules as the alternative for posting rules, providing clear usage context.

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