RLM MCP Server

Set Variable

rlm_set_variable

Idempotent

Save intermediate results during recursive language model processing by storing variables in the session for later retrieval.

Instructions

Store a variable in the session for later use.

Use this to save intermediate results during RLM processing.

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": {
      "name": "<name>"
    },
    "name": "rlm_set_variable"
  }
}

Input Schema

Name	Required	Description
`name`	Yes	Variable name
`value`	No	Variable value (any JSON-serializable value)
`session_id`	No	Session ID

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.0.0Aug 2, 2026

TDQS

A3.9/5.0

Behavior3/5

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

Annotations already provide idempotentHint=true, readOnlyHint=false, and destructiveHint=false, and the description adds session-scoping context ('in the session') and the notion of later reuse. However, it does not disclose behavior around overwriting existing variables, omitting the value, or whether a session must exist, so some gaps remain.

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 two short sentences with no filler. The core action is front-loaded in the first sentence, and the second sentence provides a concrete use case. Every word earns its place.

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

Completeness3/5

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

For a simple setter, the description is adequate, but it lacks important invocation context: it does not mention that a session must exist, what happens if value is omitted, or how session_id relates to the 'session' mentioned. With no output schema and sibling tools, a bit more guidance would make it fully complete.

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?

Schema coverage is 100%, meaning all parameters (name, value, session_id) have descriptions. The tool description adds little beyond restating 'variable' and 'session', so it meets the baseline 3 for high schema coverage but provides no extra semantic detail.

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 uses a specific verb ('Store') with a clear resource ('a variable in the session'), and the scope ('for later use') distinguishes it from sibling tools like rlm_get_variable, which retrieves variables, and rlm_load_context, which loads context. It directly states what the tool does and is unambiguous.

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

Usage Guidelines4/5

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

The description explicitly instructs when to use the tool: 'Use this to save intermediate results during RLM processing.' This gives clear context, though it does not mention alternatives or when not to use it, so it falls short of a 5.

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

Deploy Server