Skip to main content
Glama

ToolMux v2.3

Efficient MCP server aggregation with FastMCP 3.x foundation

ToolMux proxies multiple MCP (Model Context Protocol) servers through a single interface, reducing token overhead while maintaining full tool access. It supports five operating modes optimized for different use cases.

Architecture

ToolMux architecture

Related MCP server: MCP Server Proxy

Features

  • FastMCP 3.x Foundation — Proper MCP protocol compliance via FastMCP framework

  • Five Operating Modes — Meta (80%+ savings), Gateway (60%+ savings), Proxy (native fastmcp), Search (85%+ savings), Code (90%+ savings)

  • Native Proxy Mode — Uses fastmcp 3.0's create_proxy() for true transparent proxying with session isolation and MCP feature forwarding

  • CondenseTransform — Token optimization via fastmcp's Transform system: condensed descriptions/schemas in tools/list, full details on demand via helper tools

  • Smart Description Condensation — First-sentence extraction with filler phrase removal

  • Schema Condensation — Strips verbose extras, keeps names/types/required

  • Progressive Disclosure — Full descriptions via list_all_tools() and get_tool_schema(), condensed in tools/list

  • Self-Healing Bundle Resolution — Auto-resolves broken server configs from mcp-registry, user bundles, XDG, Claude Desktop, and Cursor bundles

  • Parallel Backend Init — Thread pool (10 workers, 30s timeout) for fast startup

  • MCP Instructions — All modes embed instructions in the MCP initialize response telling the LLM to call list_all_tools() first

  • LLM-Powered Description Optimizationoptimize_descriptions tool lets the connected LLM generate high-quality tool descriptions, replacing algorithmic condensation

  • Tool Collision Resolution — Automatic server-name prefixing for duplicate tool names

Installation

# Via PyPI
pip install toolmux

# Via uvx (recommended, no install needed)
uvx toolmux

# From source
git clone https://github.com/subnetangel/ToolMux.git
cd ToolMux
pip install -e .

# Verify
toolmux --version

Quick Start

1. Configure backend servers

Create ~/shared/toolmux/mcp.json (or ~/toolmux/mcp.json):

{
  "mode": "gateway",
  "servers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/home/user"]
    },
    "git": {
      "command": "uvx",
      "args": ["mcp-server-git", "--repository", "/path/to/repo"]
    }
  }
}

2. Run ToolMux

# Default gateway mode
toolmux

# Specific mode
toolmux --mode meta
toolmux --mode proxy

# Custom config
toolmux --config /path/to/mcp.json

3. Use with any MCP client

Add to your MCP client configuration (e.g., Claude Desktop, Cursor, Kiro, VS Code):

{
  "mcpServers": {
    "toolmux": {
      "command": "toolmux",
      "args": ["--mode", "gateway"]
    }
  }
}

Operating Modes

ToolMux offers three modes that trade off between token savings and tool transparency. All modes share a common set of helper tools (list_all_tools, get_tool_schema, get_tool_count, manage_servers, optimize_descriptions) and embed MCP instructions telling the LLM to call list_all_tools() first.

Mode Comparison

Gateway (default)

Meta

Proxy

Search (new)

Code (new)

Token savings

~60-85%

~80-93%

~69%

~85-95%

~90-97%

tools/list size

1 tool per server + helpers

5 meta-tools

All backend tools (condensed)

2 synthetic + helpers

3 synthetic + helpers

Tool invocation

server(tool="name", arguments={...})

invoke(name="name", args={...})

tool_name(param="value")

call_tool(name="name", arguments={...})

execute(code="await call_tool(...)")

Backend init

BackendManager (parallel threads)

BackendManager (parallel threads)

fastmcp create_proxy()

fastmcp create_proxy()

fastmcp create_proxy()

Best for

Balanced savings + usability

Maximum savings, many servers

Full MCP compliance, advanced features

Large catalogs (100+ tools)

Multi-step workflows

Gateway Mode (Default) — ~60-85% Token Savings

Collapses each backend server into a single tool. The LLM sees one tool per server (e.g., filesystem, git) instead of dozens of individual tools. Each server-tool's description lists all its sub-tools with their purpose and required parameters.

How it works:

  1. On startup, BackendManager initializes all backends in parallel (10-worker thread pool, 30s timeout). If a build cache exists (.toolmux_cache.json), tools are loaded instantly from cache and backends init in the background.

  2. Tools are grouped by server. For each server, a single FastMCP tool is registered with a rich description listing all sub-tools (e.g., "Tools: read_file (Read complete file contents; required: path), write_file (...), ...").

  3. The LLM calls list_all_tools() first to discover all available tools with full descriptions.

  4. To invoke a sub-tool, the LLM calls the server-tool with tool= and arguments= parameters: filesystem(tool="read_file", arguments={"path": "/tmp/example.txt"}).

  5. On first invocation of each sub-tool, the response is enriched with the full description and parameter schema (progressive disclosure). On errors, the full schema is always appended.

tools/list returns:
  - filesystem (server-tool): "Tools: read_file, write_file, ..."
  - git (server-tool): "Tools: git_status, git_log, ..."
  - list_all_tools (native): MUST call first — full descriptions grouped by server
  - get_tool_schema (native): Get full parameter details for any tool
  - get_tool_count (native): Get tool count statistics by server
  - manage_servers (native): Add, remove, validate, test backend servers
  - optimize_descriptions (native): LLM-powered description optimization

Calling pattern:
  list_all_tools()  # discover all tools with full descriptions
  filesystem(tool="read_file", arguments={"path": "/tmp/example.txt"})

Token savings mechanism: Instead of exposing N tools with full descriptions and schemas in tools/list, gateway exposes ~S server-tools (where S << N) plus helper tools. Descriptions are condensed to first-sentence + required params. Full details are disclosed progressively on first use.

Meta Mode — ~80-93% Token Savings

Exposes only 5 generic meta-tools regardless of how many backend tools exist. The LLM discovers tools via list_all_tools() / catalog_tools(), inspects schemas via get_tool_schema(), and executes via invoke().

How it works:

  1. Same BackendManager parallel init as gateway mode.

  2. Instead of registering per-server or per-tool entries, 5 fixed tools are registered: list_all_tools, catalog_tools, get_tool_schema, invoke, get_tool_count.

  3. catalog_tools() returns a JSON array of all backend tools with name, server, condensed description, and parameter names.

  4. get_tool_schema(name="tool_name") returns the full description and inputSchema for a specific tool.

  5. invoke(name="tool_name", args={...}) routes the call to the correct backend server. Results are enriched with full docstrings on first invocation.

tools/list returns:
  - list_all_tools: MUST call first — full descriptions grouped by server
  - catalog_tools: List all backend tools with name, server, description
  - get_tool_schema: Get full schema for a tool
  - invoke: Execute a backend tool
  - get_tool_count: Tool count by server
  - manage_servers: Add, remove, validate, test backend servers
  - optimize_descriptions: LLM-powered description optimization

Workflow: list_all_tools() → get_tool_schema("tool") → invoke("tool", args)

Token savings mechanism: tools/list always returns exactly 7 tools (5 meta + 2 management) regardless of backend count. A setup with 200 backend tools still only shows 7 in tools/list. The tradeoff is an extra round-trip: the LLM must call get_tool_schema() before invoke() to know the parameters.

Proxy Mode — Native FastMCP Proxy with Token Optimization

Uses fastmcp 3.0's native create_proxy() for true transparent proxying. All backend tools are exposed directly — the LLM calls them by name just like normal MCP tools. Token optimization is applied via CondenseTransform, which condenses descriptions and schemas in tools/list while helper tools return full uncondensed details.

How it works:

  1. Server configs are converted to standard mcpServers format and passed to create_proxy(), which creates a FastMCP proxy with MCPConfigTransport for each backend.

  2. CondenseTransform (a fastmcp Transform subclass) is applied to the proxy. It intercepts tools/list responses and replaces each tool's description with a condensed version (first sentence, filler removed, max 80 chars) and each schema with a minimal version (property names + types + required only).

  3. Helper tools (list_all_tools, get_tool_schema, get_tool_count) are registered directly on the proxy. They query the proxy's internal tool list before the transform is applied, so they return full uncondensed descriptions and schemas.

  4. For multi-server setups, tools are prefixed as {server}_{tool} (e.g., filesystem_read_file). Single-server setups leave tools unprefixed.

  5. Sessions are persistent and reused across tool calls (fastmcp 3.1.1+).

tools/list returns all backend tools with CONDENSED descriptions/schemas.
  - Single server: tools unprefixed (echo_tool)
  - Multi server: tools prefixed as {server}_{tool}

Helper tools (return FULL uncondensed info):
  - list_all_tools(): MUST call first — full descriptions grouped by server
  - get_tool_schema(name): full description + full inputSchema
  - get_tool_count(): tool counts by server
  - manage_servers: Add, remove, validate, test backend servers

Call directly: echo_tool(message="hello")

Proxy mode features:

  • True transparent proxying via fastmcp's MCPConfigTransport

  • Session isolation per request

  • Automatic MCP feature forwarding (sampling, elicitation, logging, progress)

  • CondenseTransform for ~69% token reduction in tools/list

  • Progressive disclosure: condensed by default, full on demand via helper tools

Token savings mechanism: All tools appear in tools/list (unlike gateway/meta), but descriptions are condensed from paragraphs to single sentences and schemas are stripped to names/types/required. The LLM calls list_all_tools() once to get full descriptions, then calls tools directly.

Search Mode — ~85-95% Token Savings

Uses FastMCP's BM25SearchTransform to replace the full tool catalog with ranked search. The LLM discovers tools by querying search_tools(query="what I need") and gets back only the top-k relevant results. Execution via call_tool(name, arguments).

How it works:

  1. Same per-server proxy setup as proxy mode (error isolation, session persistence)

  2. BM25SearchTransform intercepts tools/list — replaces all backend tools with search_tools and call_tool

  3. BM25 indexes tool names, descriptions, and parameter names for natural language ranking

  4. Helper tools (list_all_tools, get_tool_schema, get_tool_count) bypass the transform for full catalog access

tools/list returns:
  - search_tools: Find tools by natural language query (BM25 ranked)
  - call_tool: Execute any tool by name
  - list_all_tools: Full catalog grouped by server
  - get_tool_schema: Full parameter details
  - get_tool_count: Tool count statistics
  - manage_servers: Backend management

Workflow: search_tools("read file") → call_tool("filesystem_read_file", {"path": "..."})

Token savings mechanism: The LLM never sees tools it doesn't need. A search for "calendar" against 258 tools returns ~10 relevant results (~400 tokens) instead of the full catalog (~5,000 tokens).

Code Mode — ~90-97% Token Savings

Uses FastMCP's experimental CodeMode transform for sandboxed multi-step execution. The LLM discovers tools via BM25 search, then writes Python code that chains multiple call_tool() calls in a sandbox. Intermediate results stay in the sandbox — only the final result enters the context window.

How it works:

  1. Same per-server proxy setup as proxy mode

  2. CodeMode replaces tools with search, get_schema, and execute

  3. execute(code) runs Python in a pydantic-monty sandbox with call_tool() available

  4. Multiple tool calls can be chained in a single execute() invocation

  5. Helper tools bypass the transform for full catalog access

tools/list returns:
  - search: Find tools by query (BM25 ranked, with detail levels)
  - get_schema: Get parameter details for specific tools
  - execute: Run Python code with call_tool() in sandbox
  - list_all_tools: Full catalog grouped by server
  - get_tool_count: Tool count statistics
  - manage_servers: Backend management

Workflow: search("calendar") → get_schema(["calendar_view"]) → execute("result = await call_tool(...)")

Token savings mechanism: Multi-step workflows execute in one round-trip. Intermediate results (e.g., raw API responses passed between tools) never enter the context window — they exist only inside the sandbox.

Shared Features

Progressive Disclosure

All modes use progressive disclosure to minimize tokens while keeping full information accessible:

  1. tools/list — Condensed descriptions and schemas (what the LLM sees on connect)

  2. list_all_tools() — Full descriptions grouped by server (LLM calls this first)

  3. get_tool_schema(name) — Full description + complete inputSchema for a specific tool

  4. First-use enrichment (gateway/meta only) — On the first invocation of each tool, the response includes the full description and parameter schema appended to the result

Description Condensation

The condense_description() function:

  1. Normalizes whitespace (collapses newlines and multiple spaces)

  2. Removes filler phrases ("Use this tool to", "This tool allows you to", etc.)

  3. Capitalizes the first letter after filler removal

  4. Extracts the first sentence (up to ., !, or ?)

  5. Trims to 80 characters without cutting mid-word

Schema Condensation

The condense_schema() function strips schemas down to:

  • Property names and types

  • Array item types

  • Required field list

Removed: descriptions, defaults, examples, enums, pattern constraints, nested object details.

LLM-Powered Description Optimization

The optimize_descriptions tool lets the connected LLM generate higher-quality descriptions than the algorithmic condensation:

  1. optimize_descriptions(action="generate") — Returns all tools with full descriptions

  2. The LLM writes concise (<60 char) descriptions for each tool

  3. optimize_descriptions(action="save", server="name", descriptions={...}) — Saves to cache

  4. Restart ToolMux to use the optimized descriptions

Use optimize_descriptions(action="status") to check if descriptions have been optimized.

Build Cache

ToolMux caches tool descriptions in .toolmux_cache.json next to the config file. The cache is validated against a SHA-256 hash of mcp.json — any config change invalidates it.

  • Cache hit: Tools load instantly from cache. Backends init in the background for actual tool calls.

  • Cache miss: Server names are registered as placeholders immediately (so mcp.run() starts without delay). Backends init in the background. A cache is auto-generated once backends finish.

Server Management

The manage_servers tool provides runtime server management:

  • manage_servers(action="list") — List all configured servers

  • manage_servers(action="add", name="my-mcp", command="cmd") — Add a server (auto-resolves from bundles if no command given)

  • manage_servers(action="remove", name="my-mcp") — Remove a server

  • manage_servers(action="validate") — Check all server commands exist on PATH

  • manage_servers(action="test", name="my-mcp") — Start server and verify it returns tools

Self-Healing Bundle Resolution

When a configured server command fails or returns 0 tools, ToolMux automatically searches for the correct launch config in these locations (in order):

  1. mcp-registry bundles (~/.config/smithy-mcp/bundles/)

  2. User bundles (~/.aim/bundles/)

  3. XDG mcp config (~/.config/mcp/mcp.json)

  4. Claude Desktop (~/.claude/claude_desktop_config.json)

  5. Cursor (~/.cursor/mcp.json)

If a fix is found, it's persisted back to mcp.json so it only happens once.

CLI Reference

toolmux [OPTIONS]

Options:
  --mode {gateway,meta,proxy,search,code}  Operating mode (default: gateway)
  --config PATH                Path to mcp.json config file
  --version                    Print version and exit
  --list-servers               List configured servers and exit
  --build-cache                Generate LLM description cache and exit
  --manage [list|add|remove|validate|test]  Manage backend servers

Configuration

Config File Discovery Order

  1. --config flag (explicit path)

  2. ./mcp.json (project-local)

  3. ~/shared/toolmux/mcp.json (shared environments — persists across sessions)

  4. ~/toolmux/mcp.json (local installs)

  5. First-run setup creates ~/shared/toolmux/mcp.json

Config Format

{
  "mode": "gateway",
  "cache_model": "us.anthropic.claude-3-5-haiku-20241022-v1:0",
  "servers": {
    "server-name": {
      "command": "npx",
      "args": ["-y", "package-name"],
      "env": {"KEY": "value"},
      "cwd": "/optional/working/dir",
      "description": "Optional human description"
    },
    "http-server": {
      "transport": "http",
      "base_url": "https://api.example.com/mcp",
      "headers": {"Authorization": "Bearer token"},
      "timeout": 30
    }
  }
}

Architecture

MCP Client (Agent/IDE)
    ↕ stdio JSON-RPC
FastMCP Server (ToolMux)
    ├── Mode Router → meta | gateway | proxy | search | code
    │
    ├── Gateway/Meta Mode
    │   ├── BackendManager (parallel init, tool routing)
    │   ├── Pure Functions (condense, enrich, collisions)
    │   ├── Build Cache (SHA-256 validated, auto-generated)
    │   ├── Self-Healing Bundle Resolution
    │   └── manage_servers + optimize_descriptions
    │
    ├── Proxy Mode (fastmcp native)
    │   ├── create_proxy(mcpServers config)
    │   ├── CondenseTransform (token optimization)
    │   ├── Helper tools (list_all_tools, get_tool_schema, get_tool_count)
    │   ├── manage_servers
    │   └── Session isolation + MCP feature forwarding
    │
    ├── Search Mode (fastmcp native)
    │   ├── create_proxy(mcpServers config)
    │   ├── BM25SearchTransform (replaces catalog with search_tools + call_tool)
    │   ├── Helper tools (list_all_tools, get_tool_schema, get_tool_count)
    │   └── manage_servers
    │
    └── Code Mode (fastmcp native)
        ├── create_proxy(mcpServers config)
        ├── CodeMode transform (search + get_schema + execute sandbox)
        ├── pydantic-monty sandbox (intermediate results stay in sandbox)
        ├── Helper tools (list_all_tools, get_tool_count)
        └── manage_servers

Development

# Install in development mode
pip install -e ".[dev]"

# Run tests
python3 -m pytest tests/ -v

# Run with benchmark output
python3 -m pytest tests/test_token_optimization.py -v -s

Test Suite

File

Tests

Coverage

test_pure_functions.py

24

Property-based (hypothesis) + unit tests for all pure functions

test_list_all_tools.py

20

list_all_tools across all modes, server filtering, cache integration

test_bundle_resolution.py

20

Self-healing bundle resolution across 5 config sources

test_config_cli.py

15

Config discovery, CLI args, version sync, build cache

test_backend.py

11

BackendManager, HttpMcpClient, parallel init

test_protocol_e2e.py

11

MCP protocol compliance, end-to-end mode workflows

test_token_optimization.py

6

Token savings benchmarks per mode

Total

107

0 failures

Version History

Version

Changes

2.1.0

Native proxy mode via fastmcp create_proxy(), CondenseTransform for proxy token optimization, helper tools (list_all_tools/get_tool_schema/get_tool_count) bypass transform in proxy mode, session isolation per request, MCP feature forwarding (sampling, elicitation, logging, progress)

2.0.8

list_all_tools in all modes, MCP instructions in initialize response, .gitignore bundle fix

2.0.7

Self-healing bundle resolution (5 config sources), 8 test fixes, publish script symlink fix

2.0.6

list_all_tools gateway tool with server filtering and cached description support

2.0.5

Cache-first startup (no more init timeout), graceful stdin EOF handling, stderr suppression, version sync

2.0.0

Initial v2: FastMCP foundation, 3 operating modes, BackendManager, parallel init, smart condensation, build cache, collision resolution

License

MIT

Available Tools

7 tools
filesystemC

Tools: filesystem (Local filesystem access - read, write, and manage files)

ParametersJSON Schema
NameRequiredDescriptionDefault
toolNo
argumentsNo

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

C2.4/5.0
Behavior2/5

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

With no annotations, the description must disclose behavioral traits but only gives a high-level summary. It does not warn about destructive operations, permission requirements, scope, or the nature of the 'tool' and 'arguments' parameters, leaving significant behavioral ambiguity.

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 a single concise sentence that front-loads the core purpose. However, it is so brief that it sacrifices substance, bordering on under-specification rather than effective brevity.

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

Completeness1/5

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

Given the tool's dispatcher-like schema (tool + arguments) and lack of annotations or parameter explanations, the description is grossly incomplete. It leaves the agent without enough information to correctly invoke the tool or understand what arguments are valid.

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

Parameters1/5

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

The input schema has two parameters ('tool' and 'arguments') with zero schema description coverage. The description provides no explanation of what these parameters mean or how they map to filesystem operations, so it does not compensate for the missing schema detail.

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

Purpose4/5

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

The description clearly states the tool provides 'Local filesystem access' with operations 'read, write, and manage files', giving a specific verb+resource combination. It is distinct from the listed sibling tools (e.g., brave-search, manage_servers), though it lacks detail on what 'manage' entails.

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

Usage Guidelines2/5

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

No guidance is provided on when to use this tool versus alternatives. The description only implies usage for local filesystem operations but does not mention any exclusions, prerequisites, or comparisons to sibling tools.

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

get_tool_countA

Get count of available tools by server.

ParametersJSON Schema
NameRequiredDescriptionDefault

No parameters

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

A3.8/5.0
Behavior3/5

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

With no annotations, the description must disclose behavioral traits itself. 'Get count' implies a read-only operation, but it does not explain whether it requires authentication, how it groups by server, or if there are any limitations. The description is adequate but minimal for a simple count tool.

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 a single, concise sentence that uses clear noun-verb structure. No wasted words or redundant details.

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

Completeness4/5

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

For a zero-parameter tool with an output schema present, the description sufficiently conveys the purpose. It could add detail about the output format, but the output schema likely covers that. The behavior is simple and the description is complete enough for the context.

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 the schema fully covers this with an empty properties object. The description correctly implies no input is needed, so there is no missing parameter information to compensate for.

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 verb 'Get count' and the resource 'available tools by server', which distinguishes it from sibling tools like list_all_tools (which likely returns full details) and get_tool_schema (which returns schemas).

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

Usage Guidelines2/5

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

The description provides no explicit guidance on when to use this tool instead of alternatives like list_all_tools or get_tool_schema. It is left to the agent to infer that this is for a lightweight count rather than full details.

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

get_tool_schemaA

Get full description and inputSchema for a specific tool.

ParametersJSON Schema
NameRequiredDescriptionDefault
nameYes

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

A3.6/5.0
Behavior3/5

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

No annotations are provided, so the description carries the full burden. It communicates a read-only 'Get' operation but does not disclose details such as error handling, case sensitivity, or whether the operation has side effects. It adds minimal behavioral context beyond the literal function.

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 a single, front-loaded sentence that efficiently states the action and target. It is appropriately concise for a simple tool, though it could include slightly more context without becoming verbose.

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 tool with one parameter and an output schema, the description covers the core purpose but lacks usage guidance. It does not mention how to get a valid tool name or when to use this tool instead of list_all_tools. The output schema likely covers return values, but the description alone is only moderately 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?

The input schema has one required parameter 'name' with no description, and schema coverage is 0%. The description adds that the schema is for 'a specific tool,' which clarifies that 'name' refers to a tool name, providing a small semantic layer. However, it does not specify the expected format or how to obtain valid names, such as via list_all_tools.

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 the specific verb 'Get' to indicate retrieval, and specifies the resource as 'full description and inputSchema for a specific tool.' This clearly distinguishes it from sibling tools like list_all_tools (which lists all tools) and get_tool_count (which counts tools), as it targets a single tool's schema.

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

Usage Guidelines3/5

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

The phrase 'for a specific tool' implies the tool is used when you need schema details for one tool, but it does not explicitly state when to use it versus alternatives. It lacks any mention of list_all_tools as a way to discover valid tool names or any contextual guidance.

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

list_all_toolsA

List all tool names and descriptions grouped by server. Optionally filter by server name.

ParametersJSON Schema
NameRequiredDescriptionDefault
serverNo

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

A4.4/5.0
Behavior4/5

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

With no annotations provided, the description fully carries the burden of behavioral disclosure. It clearly states the output behavior (list names and descriptions grouped by server) and that filtering is optional. No hidden side effects or additional traits need disclosure for such a simple listing operation.

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: the first states the core function, the second explains the optional filter. Every word earns its place, and the most important information is front-loaded.

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 one-optional-parameter tool with an output schema, the description is complete. It covers what is listed, how it is grouped, and the only parameter's purpose. There is no missing information that would prevent an agent from using it correctly.

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

Parameters5/5

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

Even though the schema provides no parameter descriptions (0% coverage), the description explains the 'server' parameter as an optional filter by server name. This compensates fully for the schema's lack of detail and adds clear meaning to the parameter.

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 a specific action ('List all tool names and descriptions') and the grouping key ('grouped by server'). It also distinguishes itself from sibling tools like get_tool_schema (which retrieves a single tool's schema) and get_tool_count (which counts tools) by focusing on listing all tools in a grouped format.

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

Usage Guidelines3/5

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

The description implies the tool is for obtaining an overview of available tools, optionally filtered by server. However, it does not explicitly compare with siblings like get_tool_schema or get_tool_count, leaving the choice of when to use this versus those tools to inference.

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

manage_serversB

Manage ToolMux backend MCP servers. Actions: list, add, remove, validate, test, retry.

Examples: manage_servers(action="list") manage_servers(action="add", name="my-mcp", command="my-mcp-server", description="My MCP") manage_servers(action="remove", name="my-mcp") manage_servers(action="validate") manage_servers(action="test", name="my-server") manage_servers(action="retry", name="aws-sentral-mcp")

ParametersJSON Schema
NameRequiredDescriptionDefault
argsNo
nameNo
actionYes
commandNo
base_urlNo
transportNo
descriptionNo

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

B3.2/5.0
Behavior2/5

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

With no annotations, the description must disclose behavioral traits, but it only lists actions without describing side effects, destructive nature (e.g., 'remove'), permissions required, or impact of test/retry operations. The examples show invocation but not consequences, leaving significant transparency gaps for a management 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 concise, front-loaded with the purpose, and uses examples effectively to illustrate usage. The example list is longer than strictly necessary but each line earns its place by clarifying action-parameter combinations.

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?

Given the tool's complexity (7 parameters, 6 actions) and no annotations, the description is not fully complete: it lacks per-action parameter requirements and edge cases. An output schema exists, so return values are not needed, but the action-parameter mapping remains underspecified.

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 description coverage is 0%, and the description partly compensates by demonstrating usage of name, command, and description in examples. However, it does not explain parameters like args, base_url, or transport, nor how parameters vary across actions, so it adds only partial meaning beyond the schema.

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

Purpose4/5

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

The description states it 'Manage[s] ToolMux backend MCP servers' and enumerates concrete actions (list, add, remove, validate, test, retry), making the tool's purpose clear. It distinguishes from siblings that focus on tool schema/count/list or file operations, though 'manage' is somewhat broad and relies on the action list for specificity.

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

Usage Guidelines3/5

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

Usage is implied through examples such as adding or removing a server with specific parameters, but there is no explicit guidance on when to use this tool versus alternatives like list_all_tools or when not to use it. No exclusions or alternative tool references are provided, so the guidance is present but implicit.

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

optimize_descriptionsA

Optimize ToolMux tool descriptions using your intelligence as the LLM. Produces higher-quality descriptions than the auto-generated algorithmic ones.

Actions: status — Check if descriptions have been optimized or are still algorithmic. generate — Returns all tools with their full descriptions. Read them and generate concise (<60 char) versions. save — Save your optimized descriptions for a server.

Workflow:

  1. optimize_descriptions(action="generate") → review all tools

  2. For each server, write concise descriptions capturing the action verb and key object

  3. optimize_descriptions(action="save", server="server_name", descriptions={"tool1": "desc1", ...})

  4. Restart ToolMux to use optimized descriptions

ParametersJSON Schema
NameRequiredDescriptionDefault
actionYes
serverNo
descriptionsNo

Output Schema

ParametersJSON Schema
NameRequiredDescription
resultYes

TDQS

A4.5/5.0
Behavior4/5

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

With no annotations, the description carries the full burden. It discloses the three actions (status, generate, save), the workflow, and the important consequence that a restart is required after saving. It does not detail all side effects or return behaviors, but the output schema presumably covers return values. This is more transparent than a simple 'update' tool.

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 well-organized with a brief purpose statement, a categorized action list, and a numbered workflow. Every sentence provides useful information—no filler or redundancy. It is concise enough despite covering multiple actions.

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

Completeness4/5

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

The tool has moderate complexity (three actions, output schema exists). The description includes purpose, actions, workflow, and the restart requirement. It does not describe the exact return format, but that is likely in the output schema. Overall, it is sufficiently complete for an agent to use the tool correctly.

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

Parameters5/5

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

Schema description coverage is 0%, but the description fully compensates by explaining each parameter in the workflow. It explicitly shows action values ('generate', 'save', 'status'), the server parameter ('server="server_name"'), and the descriptions object format ({"tool1": "desc1", ...}). This gives complete semantics beyond the bare schema.

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 states a clear verb + object: 'Optimize ToolMux tool descriptions'. It distinguishes itself from sibling tools like list_all_tools or get_tool_schema by focusing on improving descriptions rather than retrieving them.

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 provides an explicit numbered workflow: generate → review → save → restart. It explains when to use the tool by framing it as producing higher-quality descriptions than algorithmic versions. It does not explicitly mention when not to use it or alternatives, but the workflow gives clear context for use.

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

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

  1. 7 tool updatesv2.3.1
    • First observedbrave-search
    • First observedfilesystem
    • First observedget_tool_count
    • First observedget_tool_schema
    • First observedlist_all_tools
    • First observedmanage_servers
    • First observedoptimize_descriptions

TDQS

B3.2/5.0

Scored across 7 tools

Disambiguation4/5

Most tools have clearly distinct purposes: introspection (get_tool_schema, get_tool_count, list_all_tools), server management (manage_servers), and description optimization (optimize_descriptions). However, 'filesystem' and 'brave-search' are ambiguous as they appear to be single tools but actually represent bundled servers, making their usage boundaries unclear.

Naming Consistency3/5

Five tools follow a consistent verb_noun pattern (get_tool_schema, get_tool_count, list_all_tools, manage_servers, optimize_descriptions). The remaining two, 'filesystem' and 'brave-search', are bare nouns with hyphens, breaking the convention and reducing consistency.

Tool Count4/5

Seven tools is a reasonable number for a server management and introspection tool. The inclusion of 'filesystem' and 'brave-search' as standalone tools is somewhat unusual but does not significantly bloat the count.

Completeness4/5

The tool set covers core operations: listing tools, fetching schemas, counting tools, managing servers (list/add/remove/validate/test/retry), and optimizing descriptions. A notable gap is the lack of an update operation for server configurations, but most common workflows are supported.

Maintenance

ActivityInactive
ResponsivenessNo issues

Related MCP Connectors

Related MCP Servers

  • F
    license
    Not graded
    quality
    D
    maintenance
    Aggregates multiple shared MCP servers into a single HTTP gateway, providing a unified, observable, and reusable MCP access layer for multiple AI clients like Codex, OpenCode, and OpenClaw. It centralizes configuration management, logging, health checks, and circuit breaking to simplify multi-client MCP deployments.
    5
    -
  • A
    license
    Not graded
    quality
    D
    maintenance
    Aggregates multiple MCP servers into a single endpoint, enabling LLM clients to access tools, resources, and prompts from various backends through one connection.
    6 npm
    MIT
  • F
    license
    Not graded
    quality
    B
    maintenance
    Aggregates multiple MCP servers and custom Python tools behind a single endpoint, with intelligent context and tool discovery for AI agents.
    -
  • A
    license
    A
    quality
    B
    maintenance
    Aggregates multiple MCP servers into a single interface, reducing token overhead and simplifying tool management for LLMs.
    6
    197 npm
    18
    Apache 2.0