name: mcp-planning description: > Ideation and planning phase for MCP server development. Use when planning a new MCP server, clarifying purpose and scope, choosing between stdio and SSE transport, inventorying which tools resources and prompts to expose, assessing client compatibility, defining success criteria, or documenting the interface contract before writing any code. Covers purpose definition, transport selection, capability inventory, and client environment analysis.

MCP Planning

Ideation and scope definition before MCP server implementation begins.

Intent Router

Load reference files on demand — only when the corresponding topic is active:

• references/transport-selection.md — Load when transport choice is unsettled, involves remote deployment, or multiple clients must connect simultaneously
• references/client-compatibility.md — Load when the target client is anything other than a local stdio host, or when multi-client support is required

Quick Start — Planning Outputs

Produce these four outputs before any code is written:

Planning is complete when all four outputs are documented.

Phase: Purpose Definition

Establish the server's reason for existence before building the capability inventory. Document: what domain problem it solves, who the primary client is, what tools it must expose (named), whether resources or prompts are needed.

Scope limit: one server = one domain. A file-system server does not also become a database connector. If the purpose statement covers more than one domain, split into two servers.

Trigger phrases to document (3+): how would a user phrase the request that causes the agent to call this server's tools?

Phase: Capability Inventory

List every tool, resource, and prompt the server will expose. Use this table:

| Type     | Name              | Description (≤15 words)                  | Required |
|----------|-------------------|------------------------------------------|----------|
| tool     | read_file         | Read a file from the local filesystem    | Yes      |
| resource | file://{path}     | URI template for file access             | No       |
| prompt   | summarize_file    | Template: summarize the file at {path}   | No       |

The Required column means required for the server's primary purpose (not by the MCP spec). Mark tools that must exist for the server to be useful as Yes; mark optional enhancements as No. Required=No items may be deferred to a later iteration.

Limit: if the inventory exceeds 10 tools, consider splitting into two servers. Resources and prompts are optional — most servers expose only tools.

Phase: Transport Selection

Load references/transport-selection.md for the full decision matrix.

Quick rule:

• stdio — local process, local desktop client, default choice
• SSE — remote deployment, multi-client access, requires HTTP infrastructure

When in doubt, use stdio. Only choose SSE when remote access is explicitly required.

Phase: Client Compatibility

Load references/client-compatibility.md when the target client is not a local stdio host.

Record which clients will connect and note any known constraints (config file locations, transport limits, tool name length limits) in the planning document.

Safety Notes

Scope drift is the primary planning risk. An inventory that grows beyond 10 tools during planning is a signal to split scope — not to proceed. Document explicit out-of-scope items to prevent scope creep during implementation.

Resource Index