OnlyMCP

Add a connection

connection_create

Connect a remote MCP server. Only http and sse servers - a stdio server runs as a child process on a machine and cannot be started on somebody else's behalf. The server is probed straight away and the result reported. Passing a secret here puts it into this conversation; leave it out and set it in the dashboard if that matters. Docs: https://only-mcp.com/docs/mcp-servers#how-a-server-signs-in

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>",
      "slug": "<slug>",
      "url": "<url>"
    },
    "name": "connection_create"
  }
}

Input Schema

Name	Required	Description
`url`	Yes	The https URL of the remote MCP endpoint.
`name`	Yes	Human readable name.
`slug`	Yes	Lowercase prefix its tools get, for example "fabbrica" gives fabbrica__list_customers.
`secret`	No	The credential. Stored encrypted, never handed back.
`teamId`	No	Share it with this team instead of keeping it private.
`authType`	No	none (default), bearer, or header.
`transport`	No	http (default) or sse.
`authHeaderName`	No	Only for authType header: which header.

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 22, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Beyond the annotations it discloses two real behaviors: the server is probed immediately with the result reported, and a passed secret is exposed in this conversation. It does not say what happens to the connection if the probe fails, which is the one operationally important gap.

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?

Four short sentences, front-loaded with the core action and the transport constraint, with no padding. The stdio explanation and the docs link are slightly expansive but each still earns its place by preventing a wrong call.

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?

Eight parameters are fully documented in the schema and the description covers the non-obvious dimensions the schema cannot: transport feasibility, probe side effects, and secret handling. With no output schema and no missing parameter, an agent has what it needs to call this correctly.

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?

Schema coverage is 100%, so the baseline is 3, and the description genuinely adds meaning: transport is limited to http/sse with stdio ruled out, and the secret parameter carries a data-exposure warning plus an alternative path (dashboard). It also points to docs for the authType/sign-in behavior rather than restating the enum.

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?

Opens with a specific verb and resource ("Connect a remote MCP server") that an agent can immediately distinguish from connection_update, connection_delete, and list_connections. The transport restriction ("Only http and sse servers") further narrows the scope in the first sentence.

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?

It gives a clear exclusion (stdio servers cannot be connected) and explicit guidance on when to pass a secret here versus setting it in the dashboard. It does not explicitly name connection_update as the tool for later modification, so usage is clear but not fully routed across siblings.

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

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