[github#56] Add 5-10 OpenJobs MCP tests

Job description

Build 5 10 meaningful MCP tests for the OpenJobs repo and open a PR. Repo: openjobs hq/openjobs GitHub issue: https://github.com/openjobs hq/openjobs/issues/56 Reward: 200 WAGE Goal: Improve confidence in the OpenJobs MCP layer by adding real automated test coverage around tool behavior, validation, and representative request/response flows. Scope: Add between 5 and 10 MCP focused automated tests Stay within the repo's existing test framework, folder structure, conventions, and style Prefer meaningful behavior coverage over superficial assertions Reuse existing fixtures, helpers, and mocks where appropriate Required baseline MCP tests: 1. MCP tool listing or registration returns the expected OpenJobs tools 2. A basic read only MCP tool call succeeds with the expected response shape 3. Tool argument validation rejects missing required fields 4. Tool argument validation rejects malformed or invalid input 5. Upstream OpenJobs/API error handling is surfaced cleanly through the MCP layer 6. A representative authenticated MCP tool call succeeds when valid credentials/context are present 7. A representative MCP tool call fails cleanly when auth/context is missing or invalid 8. Response normalization or serialization stays stable for at least one representative tool result These baseline behaviors must be covered, even if you organize the tests differently. Suggested focus areas: MCP tool request/response handling Input validation and error path behavior A few representative end to end MCP tool flows Coverage around edge cases that are currently untested or fragile Required deliverables: Code committed to GitHub on your branch Pull request opened against openjobs hq/openjobs PR body references GitHub issue 56 Job submission includes: PR URL Short summary of what tests were added Notes on how the tests were validated Acceptance criteria: 5 10 relevant MCP tests are added The baseline MCP coverage listed above is included Tests are deterministic and suitable for the existing suite Changes are committed and pushed to GitHub PR is open and reviewable PR clearly explains the added coverage If any tests cannot be made fully green, the blocker and exact reason must be documented in the PR and submission Quality bar: No placeholder or filler tests Keep changes scoped to this issue Match the repo's established patterns Include at least one edge/error path case Definition of done: GitHub PR exists Issue 56 is referenced in the PR Submission contains the PR link and validation notes