MCP: add templated tool descriptions and tool name prefixing for HTTP/STDIO servers

[nmaguiar]

Motivation

• Allow MCP servers to expose tools with a configurable external prefix while keeping internal fns/fnsMeta keys unchanged and to evaluate tool description fields as Handlebars templates using current job args.

Description

• Added new arguments tplDesc and toolPrefix with defaults and checks in both HTTP and STDIO MCP jobs to enable templated descriptions and optional tool name prefixing.
• Implemented helper functions _applyTemplateToDescriptions, _prefixToolName, _resolveToolName, and _toToolMeta to walk/transform metadata, prefix tool names for exposure, and resolve incoming prefixed names back to internal keys.
• Updated tools/list responses to return prefixed metadata produced via _toToolMeta, and updated tools/call handling to resolve the incoming params.name to the internal function key before invoking args.fns (including updating thrown/error messages accordingly).
• Adjusted STDIO MCP server to expose prefixed tool names in its fs mapping and pass prefixed metadata to ow.server.mcpStdio, while preserving internal args.fns mapping and existing error/result normalization logic.

Testing

• No automated tests were run as part of this change.

[Copilot]

Pull request overview

This PR extends the MCP HTTP and STDIO server jobs to (1) optionally render tool/metadata descriptions as Handlebars templates using the current oJob args and (2) optionally expose tools under a configurable external name prefix while keeping internal fns/fnsMeta keys unchanged.

Changes:

• Added tplDesc and toolPrefix args (with defaults/checks) to both HTTP and STDIO MCP jobs.
• Implemented metadata transformation helpers to template description fields and to prefix/resolve tool names on list/call paths.
• Updated package manifest version and included new .github artifacts in the opack file list/hash.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
oJobMCP.yaml	Adds templated tool descriptions and tool name prefixing for MCP HTTP/STDIO servers; updates tools list/call behavior accordingly.
.package.yaml	Bumps package version and includes .github assets in packaged files and hashes.

Comments suppressed due to low confidence (2)

oJobMCP.yaml:171

• In this error path you're throwing a string but later format/log the error using e.message. When e is a string, e.message is undefined, so the client will get an unhelpful message. Prefer throwing an Error (or normalizing with String(e) in the catch) so logs and responses always contain the actual message.

                      } else {
                        throw "Function not found: " + _toolName
                      }
                    } catch(e) {
                      logErr(`Error executing tool '${params.name}': ${e.message}`)
                      _res = {
                          content: [{
                              type: "text",
                              text: `Error executing tool '${params.name}': ${e.message}`
                          }],

oJobMCP.yaml:334

• Same issue as above: this handler throws a string ("Function not found: ...") but the catch block logs/returns e.message, which will be undefined for string exceptions. Throw an Error or use String(e) in the catch when building the log/response.

                    } else {
                      throw "Function not found: " + _toolName
                    }
                  } catch(e) {
                    logErr(`Error executing tool '${params.name}': ${e.message}`)
                    _res = {
                        content: [{
                            type: "text",
                            text: `Error executing tool '${params.name}': ${e.message}`
                        }],

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[Copilot]

Object.keys(args.fns).map(...) is used only for side effects (populating fs). Using map here is misleading and allocates an unused array; use forEach (or a for...of) instead to make the intent clear.

[nmaguiar]

@copilot open a new pull request to apply changes based on this feedback

[Copilot]

@nmaguiar I've opened a new pull request, #64, to work on those changes. Once the pull request is ready, I'll request review from you.