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MCP server for Postbase — schedule and publish social posts from your AI (Claude, Cursor, …).
Postbase MCP has clear, action-oriented tool names (list_*, create_*, cancel_*) and reasonable descriptions (avg 120 chars). All 5 tools have explicit Zod schemas with typed parameters and descriptions. However, output schemas are not documented, responses are JSON-stringified without field-level documentation. Error handling is minimal (raw API errors passed through). No pagination support despite list_channels and list_scheduled potentially returning large result sets. Parameter descriptions lack format constraints (e.g., ISO 8601 format stated but not validated). No tool annotations (readOnlyHint, destructiveHint) despite clear risk levels.
Cancel a scheduled post by id (returns it to draft).
Create a post. Provide channel_ids from list_channels and an ISO 8601 scheduled_at to schedule it (omit to save as a draft).
List the social channels connected to the Postbase workspace.
List posts that are scheduled to publish.
Create an X thread (multiple tweets, in order) and optionally schedule it. The first tweet is the post; the rest reply in a chain.
Output schemas not documented. Tools return JSON-stringified responses without field-level documentation. LLMs cannot plan downstream operations or extract specific fields reliably.
No pagination support. list_channels and list_scheduled lack limit/offset parameters and total count in response. Large result sets will blow context window.
Minimal error handling. API errors are passed through as raw strings without recovery guidance. LLM cannot determine if error is retryable, user-fixable, or fatal.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | B | 71 | 2026-07-28+ | v2 |
No tool annotations. Tools lack readOnlyHint, destructiveHint, or idempotentHint despite clear risk levels (READ_ONLY, WRITE, REVERSIBLE). Agents cannot reason about safety.
Parameter format constraints stated in descriptions but not validated. ISO 8601 format example given but no regex pattern or validation. LLMs may pass invalid timestamps.