Skip to main content
Glama

retroarch_state_slot_minus

Decrements RetroArch's selected save slot by one, so subsequent save/load current-state operations target the previous slot.

Instructions

PURPOSE: Decrement RetroArch's currently-selected save slot pointer by 1 (e.g. slot 3 → slot 2). USAGE: Counterpart to retroarch_state_slot_plus. Combine with retroarch_save_state_current or retroarch_load_state_current to target a lower-numbered slot — these tools always operate on the current slot. RetroArch's NCI exposes NO way to set the slot directly to N or to query the current slot number, so track it client-side or walk from a known position. For loading a specific slot WITHOUT changing the pointer, use retroarch_load_state_slot. BEHAVIOR: Mutates RetroArch's internal current-slot pointer (-1). Wraps or clamps per RetroArch's slot-cycling configuration (typically wraps at 0 → 9). FIRE-AND-FORGET: the NCI does NOT acknowledge this command — the call returns as soon as the UDP datagram is sent, with no confirmation that RetroArch received or applied it. To verify the effect, follow up with an observable tool (retroarch_get_status for run state, retroarch_read_memory / retroarch_read_ram for memory mutations, retroarch_screenshot for visual state). UDP packets to a not-listening RetroArch are silently dropped. The new slot number is NOT reported back — track it client-side or watch the on-screen slot indicator. No effect on emulator memory / run state — only the slot pointer used by future save_state_current / load_state_current calls changes. Transport: RetroArch's Network Control Interface (NCI) over UDP (default 127.0.0.1:55355, requires network_cmd_enable = true in retroarch.cfg). RETURNS: Single line 'Decremented current slot' (UDP-send confirmation only — does NOT report the new slot number).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Behavior5/5

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

With no annotations, the description fully discloses behavior: it mutates the pointer, wraps/clamps, is fire-and-forget with no acknowledgment, UDP packets are silently dropped, and no slot number is returned. It also notes no effect on emulator memory/run state. This is exemplary transparency for a network command tool.

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

Conciseness4/5

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

The description is well-structured with labeled sections (PURPOSE, USAGE, BEHAVIOR, FIRE-AND-FORGET, Transport, RETURNS) and front-loads the core purpose. However, it is somewhat verbose with minor redundancy, such as repeating that the new slot number is not reported back in both the BEHAVIOR and RETURNS sections.

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?

Given the tool's complexity (mutating RetroArch state via UDP), the description covers all necessary context: prerequisites, exact behavior, consequences, verification methods, and return value. It also addresses the lack of an output schema by explaining what the return line means.

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

Parameters4/5

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

The tool has zero parameters and an empty schema, so there is nothing to explain; baseline 4 applies. The description adds value by explaining the unspoken semantics of the operation itself, though no parameter-specific detail is needed.

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 begins with 'Decrement RetroArch's currently-selected save slot pointer by 1' which clearly states the verb, resource, and expected effect. It also distinguishes from siblings by naming retroarch_state_slot_plus and retroarch_load_state_slot, making the tool's unique role unambiguous.

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?

Explicit guidance is provided: 'Counterpart to retroarch_state_slot_plus' and 'For loading a specific slot WITHOUT changing the pointer, use retroarch_load_state_slot.' It also advises tracking the slot client-side because no direct set/query exists, giving clear context on when and how to use this tool.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/pythoninthegrass/mcp-retroarch'

If you have feedback or need assistance with the MCP directory API, please join our Discord server