@deepseek-ai/dsh-tool-search: DSH Experimental Tool Discovery Plugin

The DSH plugin `@deepseek-ai/dsh-tool-search` is an experimental tool designed to address the issue of excessively long model context in multi-tool scenarios, enabling per-agent tool discovery and progressive schema disclosure. This plugin categorizes global tools into two types: those specified via the `alwaysVisible` configuration option remain visible at all times, while other qualified tools are hidden by default and only become executable in subsequent requests when selected by the model via the scope-local `tool_search` tool. `tool_search` supports BM25-based deterministic matching, accepting a query string and an optional limit on the number of results. The plugin restricts the set of visible tools via the `ctx.tools.restrict()` interface.