Hybrid Semantic Tool Discovery for Enterprise MCP Gateway: Architecture and Implementation

From SQL Generation to Tool Selection: A Domain-Oriented Pattern for MCP Servers

The Domain-Oriented Tooling Pattern is proposed: instead of generating SQL at query time, the model selects from a small set of domain-aligned tools whose parameterized queries encapsulate schema navigation, joins and business rules on the server side.

Boundary-aware tool routing framework for large language models in vertical domains scenarios

Harness Engineering in LLM Tool Use via Agent-Native Reusable Tool Primitives

Large language models (LLMs) augmented with external tools have demonstrated remarkable capability in solving complex real-world tasks. However, existing approaches suffer from two key challenges: brittle multi-step and multi-turn reasoning caused by incompatible tool output types and API schemas, and performance degradation under large tool catalogues. To address these, we introduce \textbf{Tool Primitives}, a design that replaces rigid API schema-based invocation with natural language as the interface for tool calling, where each tool is wrapped with an LLM interface that handles schema resolution and execution internally, enabling natural inter-tool communication for nested and multi-turn tool calling. Building on Tool Primitives, we host \textbf{ToolFace}, a centralized repository of 25,519 functions from which LLMs dynamically retrieve only the relevant tools at inference time, eliminating the need to enumerate raw API schemas in context. To orchestrate Tool Primitives and ToolFace reliably in complex settings, we further propose \textbf{HEART}, a \textbf{H}arness \textbf{E}ngineering framework via \textbf{A}gent-native, \textbf{R}eusable \textbf{T}ool Primitives, comprising a Planner, Router, and Verifier that jointly support dynamic tool invocation planning, multi-step execution, and feedback-driven recovery. Experiments on five benchmarks demonstrate that HEART outperforms SFT-based models by $10\%$ on average and surpasses GPT-5.4, Claude-4.6-Sonnet, and Gemini-3.1-Pro by $6\%$ on average while reducing API cost by up to $85\%$. On 50 real-world tasks, HEART achieves $84\%$ task completion, $3.8\times$ the average of three frontier commercial models ($22\%$).

Token-Aware API Design Patterns for Model Context Protocol Integration in Enterprise Distributed Systems

This article investigates serialization-boundary optimization as a critical architectural concern for MCP-native systems and proposes four composable backend design patterns that restructure API responses to maximize semantic density while minimizing token consumption without modifying underlying domain models or persistence layers.

Scalable LLM Agent Tool Access in the Cloud

LLM agents increasingly rely on tool calling to act on external systems, and the Model Context Protocol (MCP) has quickly become its de facto interface. Operating MCP at cloud scale, however, becomes difficult. On the tool provider side, legacy services are not directly callable through MCP; the rapid protocol development also creates ongoing compatibility cost. On the agent side, the number of accessible tool is limited by the LLM context window and inference overhead; mounting a large tool set increases token usage and inference latency and can reduce task success rate. Moreover, for stateful MCP backends with multiple replicas, preserving session affinity increases client-side complexity. We present a cloud-scale gateway system for MCP service. It breaks the direct-connect model on the data plane and offloads legacy service integration, consolidating incompatible MCP variants, access control, tool recommendation, and session-aware routing to the gateway. Hybrid retrieval sustains 98% Top-15 recall; it scales agent tool access to 3,000+ with high tool selection accuracy, and reduces tool selection time by $8.9\times$ and token usage by $23.8\times$, with low per-call overhead, stable under scale-out. Finally, we share the lessons learned from deploying the gateway system in production.

MCP-Focus: Leveraging Function-Oriented Document Enhancement for MCP Server Retrieval

Model Context Protocol (MCP) has emerged as a practical standard for connecting LLM-based agents with external tools and services through MCP servers. Driven by the open-source community, the MCP ecosystem is rapidly expanding, resulting in a large and growing collection of third-party MCP servers. Accurately selecting MCP servers that satisfy functional requirements from many candidates, therefore, becomes an increasingly important problem. However, MCP server documents are often unstructured and exhibit ambiguous function semantics, making it difficult to align user requirements with server capabilities during retrieval. To address this issue, we propose MCP-Focus, a function-oriented document enhancement framework that produces retrieval-ready MCP server documentation via a multi-stage agentic pipeline for white-box code analysis and document generation. Specifically, MCP-Focus first extracts a comprehensive tool inventory with metadata, then refines tool-level descriptions grounded in each extracted tool's implementation, and finally aggregates the refined tool descriptions into a structured server-level overview as the retrieval document. To better evaluate MCP server retrieval, we construct a benchmark comprising 3k+ open-source MCP servers and human-guided queries that vary in semantic ambiguity, input-output specificity, and the number of involved function points. Experiments across multiple dense retrievers show that fine-tuning with MCP-Focus-enhanced documents consistently improves retrieval effectiveness over baseline document methods on multiple benchmarks. Code and data: https://github.com/JingWC/MCP-Focus.