use rmcp::model::Tool;
use rmcp::ErrorData;
use serde_json::{json, Map, Value};
use crate::server::tool_trait::{get_str, McpTool, ToolContext, ToolOutput};
use crate::tool_defs::tool_def;
pub struct CtxSymbolTool;
impl McpTool for CtxSymbolTool {
fn name(&self) -> &'static str {
"ctx_symbol"
}
fn tool_def(&self) -> Tool {
tool_def(
"ctx_symbol",
"Read a specific symbol (function, struct, class) by name. Returns only the symbol \
code block instead of the entire file. 90-97% fewer tokens than full file read.",
json!({
"type": "object",
"properties": {
"name": { "type": "string", "description": "Symbol name (function, struct, class, method)" },
"file": { "type": "string", "description": "Optional: file path to narrow search" },
"kind": { "type": "string", "description": "Optional: fn|struct|class|method|trait|enum" }
},
"required": ["name"]
}),
)
}
fn handle(
&self,
args: &Map<String, Value>,
ctx: &ToolContext,
) -> Result<ToolOutput, ErrorData> {
let sym_name = get_str(args, "name")
.ok_or_else(|| ErrorData::invalid_params("name is required", None))?;
let file = get_str(args, "file");
let kind = get_str(args, "kind");
let (result, original) = crate::tools::ctx_symbol::handle(
&sym_name,
file.as_deref(),
kind.as_deref(),
&ctx.project_root,
);
let sent = crate::core::tokens::count_tokens(&result);
let saved = original.saturating_sub(sent);
Ok(ToolOutput {
text: result,
original_tokens: original,
saved_tokens: saved,
mode: kind,
path: file,
})
}
}