MCP Server for storing and sampling agent trajectories with prioritized experience replay and group relative policy optimization (GRPO) advantages calculation
This server has critical gaps in definition quality. Tool descriptions are present but minimal (10-20 chars baseline). Parameter descriptions are almost entirely absent, 'steps' and 'group_trajectories' lack any explanation of expected structure or content. Input schemas exist but are severely incomplete: 'steps' is typed as array with no items schema; 'group_trajectories' items are untyped objects. No output schemas are documented. Error handling is minimal (generic 'Unknown tool' response). The server implements a specialized ML/RL domain (trajectory buffer, GRPO advantages) but fails to explain what these concepts mean or when to use each tool. An LLM cannot reliably select between add_trajectory, sample_batch, and compute_grpo_advantages without domain expertise.
Store an agent trajectory with task reward
Calculate group relative policy optimization normalized advantages
Sample prioritized trajectories with importance sampling weights
Parameter descriptions almost entirely missing. 'steps' (array of agent actions), 'group_trajectories' (array of trajectory objects), and 'batch_size' lack any explanation of expected structure, format, or semantics. LLMs cannot infer what 'steps' should contain or how to construct 'group_trajectories' objects.
Input schemas incomplete and untyped. 'steps' is array with no items schema (should specify object properties: action, code, etc.). 'group_trajectories' items are untyped objects, LLM cannot know what fields are required. 'prompt' in add_trajectory has no length constraints or format guidance.
No output schemas documented. Clients cannot predict response structure. 'sample_batch' returns trajectories, weights, indices, but no schema tells the LLM what fields each trajectory object contains or how to use the weights. 'compute_grpo_advantages' returns a list of floats with no context.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | F | 40 | 2026-07-28+ | v2 |
Tool descriptions are too brief and lack domain context. 'Store an agent trajectory with task reward' (35 chars) does not explain what a trajectory is, when to call this vs sample_batch, or what 'task reward' means. 'Calculate group relative policy optimization normalized advantages' (65 chars) assumes GRPO domain knowledge, LLM cannot infer when to use this.
Error handling is minimal and non-actionable. Generic 'Unknown tool' and 'Unknown method' responses provide no recovery guidance. Missing validation errors for invalid batch_size, empty trajectories, or malformed step objects. LLM cannot self-correct.