lean_ctx/tool_defs/

mod.rs

use std::sync::Arc;

use rmcp::model::{Tool, ToolAnnotations};
use serde_json::{Map, Value};

mod granular;
pub use granular::{granular_tool_defs, unified_tool_defs};

pub fn tool_def(name: &'static str, description: &'static str, schema_value: Value) -> Tool {
    let mut schema: Map<String, Value> = match sanitize_schema(schema_value) {
        Value::Object(map) => map,
        _ => Map::new(),
    };
    normalize_for_strict_validators(&mut schema);
    Tool::new(name, description, Arc::new(schema))
}

/// Strip root union forms rejected by strict MCP schema validators.
///
/// The combinator is removed but no required fields are added — the published
/// schema becomes more permissive and the handler does runtime validation.
/// `allOf` and conditional `anyOf` forms are preserved.
fn sanitize_schema(schema: Value) -> Value {
    let Value::Object(mut schema) = schema else {
        return schema;
    };
    // Anthropic, OpenCode, Grok, Gemini reject top-level oneOf/allOf/anyOf.
    // All conditional validation (if/then, variant-specific required) is
    // enforced at runtime by each tool's handle() method, so stripping
    // these combinators makes the schema more permissive but functionally
    // correct. (#1346)
    schema.remove("oneOf");
    schema.remove("allOf");
    schema.remove("anyOf");
    // Also strip if/then/else — they are only meaningful inside allOf
    // branches and become dead weight once allOf is removed.
    schema.remove("if");
    schema.remove("then");
    schema.remove("else");
    Value::Object(schema)
}

/// Tools that never mutate their environment (files, indexes, session state).
/// MCP clients (Cursor, Claude Desktop) may use `readOnlyHint` to allow these
/// tools in restricted/readonly subagent contexts.
///
/// Excluded from this list (despite mostly-read paths):
/// - `ctx_compose` — calls `record_access()` (co-access / session state mutation)
/// - `ctx_search` — `action=reindex` rebuilds persistent BM25 indexes
pub const READONLY_TOOL_NAMES: &[&str] = &[
    "ctx_read",
    "ctx_tree",
    "ctx_glob",
    "ctx_callgraph",
    "ctx_overview",
    "ctx_expand",
    "ctx_explore",
    "ctx_delta",
    "ctx_url_read",
    "ctx_benchmark",
    "ctx_analyze",
    "ctx_discover",
    "ctx_response",
];

/// Tools that may destructively modify their environment.
pub const DESTRUCTIVE_TOOL_NAMES: &[&str] = &["ctx_shell", "ctx_execute", "ctx_patch"];

/// Apply MCP `ToolAnnotations` (readOnlyHint, destructiveHint) to a set of
/// tool definitions. Called by the registry before serving `tools/list`.
pub fn apply_tool_annotations(tools: Vec<Tool>) -> Vec<Tool> {
    tools
        .into_iter()
        .map(|t| {
            let name = t.name.as_ref();
            if READONLY_TOOL_NAMES.contains(&name) {
                t.annotate(
                    ToolAnnotations::new()
                        .read_only(true)
                        .destructive(false)
                        .idempotent(true),
                )
            } else if DESTRUCTIVE_TOOL_NAMES.contains(&name) {
                t.annotate(ToolAnnotations::new().destructive(true))
            } else {
                t
            }
        })
        .collect()
}

/// Make a tool input schema acceptable to *strict* JSON-Schema validators.
///
/// OpenAI/Azure (Pydantic-based), Claude thinking models and OpenAI-compatible
/// backends like SGLang reject tool schemas that are valid JSON Schema but
/// omit fields the spec treats as optional. Community-reported failures
/// (OpenCode: "Invalid schema for function 'lean-ctx_ctx_expand': None is not
/// of type 'array'"):
///
/// - `type: "object"` with `properties` but no `required` → clients forward
///   `required: null` and the backend 400s. We always emit an explicit array.
/// - `type: "array"` without `items` → "array schema missing items". We emit
///   a permissive `items: {}` so the wire schema is self-contained.
///
/// Runs recursively over every nested schema position (`properties`, `items`,
/// `anyOf`/`oneOf`/`allOf`, object-shaped `additionalProperties`) so nested
/// definitions get the same guarantees. Existing `required` arrays are
/// preserved verbatim — this never changes which parameters are mandatory.
pub fn normalize_for_strict_validators(schema: &mut Map<String, Value>) {
    let is_object = schema.get("type").and_then(Value::as_str) == Some("object");
    let is_array = schema.get("type").and_then(Value::as_str) == Some("array");

    if is_object && schema.contains_key("properties") && !schema.contains_key("required") {
        schema.insert("required".into(), Value::Array(Vec::new()));
    }
    if is_array && !schema.contains_key("items") {
        schema.insert("items".into(), Value::Object(Map::new()));
    }

    if let Some(Value::Object(props)) = schema.get_mut("properties") {
        for prop in props.values_mut() {
            if let Value::Object(p) = prop {
                normalize_for_strict_validators(p);
            }
        }
    }
    if let Some(Value::Object(items)) = schema.get_mut("items") {
        normalize_for_strict_validators(items);
    }
    if let Some(Value::Object(ap)) = schema.get_mut("additionalProperties") {
        normalize_for_strict_validators(ap);
    }
    for combinator in ["anyOf", "oneOf", "allOf"] {
        if let Some(Value::Array(branches)) = schema.get_mut(combinator) {
            for branch in branches.iter_mut() {
                if let Value::Object(b) = branch {
                    normalize_for_strict_validators(b);
                }
            }
        }
    }
    for keyword in ["if", "then", "else", "not"] {
        if let Some(Value::Object(sub)) = schema.get_mut(keyword) {
            normalize_for_strict_validators(sub);
        }
    }
}

pub const CORE_TOOL_NAMES: &[&str] = &[
    "ctx_read",
    "ctx_shell",
    "shell",
    // #509: ctx_search now subsumes semantic search + symbol lookup via `action`;
    // ctx_semantic_search/ctx_symbol are deprecated aliases hidden from the surface.
    "ctx_search",
    "ctx_glob",
    "ctx_tree",
    "ctx_session",
    "ctx_compose",
    // #578: the injected INTENT playbook routes "callers/impact" to
    // ctx_callgraph, so the advertised core matches the rules. ctx_graph
    // (file-level deps, ~300 tok schema) stays reachable via ctx_call and the
    // standard/power profiles.
    "ctx_callgraph",
    // #1008 anchored editing: the rules route "edit after reading" to ctx_patch,
    // so the default surface must advertise it — but only where it earns its
    // tokens. Clients with a reliable native str-replace editor (Cursor, Zed,
    // Windsurf, …) skip it via the lazy-core client quirk in
    // `server::tool_visibility::ClientQuirks`; Claude Code, SDK harnesses and
    // unknown/headless clients get it.
    "ctx_patch",
    "ctx_call",
    "ctx_expand",
];

pub fn core_tool_names() -> &'static [&'static str] {
    CORE_TOOL_NAMES
}

pub fn lazy_tool_defs() -> Vec<Tool> {
    let all = granular_tool_defs();
    all.into_iter()
        .filter(|t| CORE_TOOL_NAMES.contains(&t.name.as_ref()))
        .collect()
}

pub fn discover_tools(query: &str) -> String {
    // Derived from the registry (single source of truth) so discovery results
    // never drift from the advertised tool schemas (#141).
    let all = crate::server::registry::build_registry().tool_defs();
    let query_lower = query.to_lowercase();
    let matches: Vec<(String, String)> = all
        .iter()
        .filter_map(|t| {
            let name = t.name.as_ref();
            let desc = t.description.as_deref().unwrap_or("");
            if name.to_lowercase().contains(&query_lower)
                || desc.to_lowercase().contains(&query_lower)
            {
                Some((name.to_string(), desc.to_string()))
            } else {
                None
            }
        })
        .collect();

    if matches.is_empty() {
        return format!(
            "No tools found matching '{query}'. Try broader terms like: graph, cost, session, search, compress, agent, workflow, gain."
        );
    }

    let mut out = format!("{} tools matching '{query}':\n", matches.len());
    for (name, desc) in &matches {
        // First line only — registry descriptions can be multi-line.
        let first = desc.lines().next().unwrap_or(desc);
        let short = if first.len() > 80 {
            &first[..first.floor_char_boundary(80)]
        } else {
            first
        };
        out.push_str(&format!("  {name} — {short}\n"));
    }
    out.push_str(
        "\nIf your MCP client registers tools only once at startup (static tools/list), \
use ctx_call (available in lazy mode) to invoke discovered tools:\n\
  ctx_call {\"name\":\"ctx_graph\",\"arguments\":{\"action\":\"status\"}}\n",
    );
    out
}

pub fn is_full_mode() -> bool {
    std::env::var("LEAN_CTX_FULL_TOOLS").is_ok_and(|v| v != "0" && !v.eq_ignore_ascii_case("false"))
        || std::env::var("LEAN_CTX_LAZY_TOOLS")
            .is_ok_and(|v| v == "0" || v.eq_ignore_ascii_case("false"))
}

#[cfg(test)]
mod tests {
    use serde_json::json;

    use super::sanitize_schema;

    #[test]
    fn sanitize_schema_strips_all_combinators() {
        let sanitized = sanitize_schema(json!({
            "type": "object",
            "properties": {"command": {"type": "string"}},
            "required": ["base"],
            "oneOf": [
                {"required": ["command", "cwd"]},
                {"required": ["command", "timeout"]}
            ],
            "allOf": [
                {"if": {"properties": {"action": {"const": "x"}}}, "then": {"required": ["y"]}}
            ],
            "anyOf": [{"type": "object"}],
            "if": {"properties": {"action": {"const": "z"}}},
            "then": {"required": ["w"]}
        }));

        assert_eq!(
            sanitized,
            json!({
                "type": "object",
                "properties": {"command": {"type": "string"}},
                "required": ["base"]
            })
        );
    }

    #[test]
    fn sanitize_schema_preserves_schema_without_one_of() {
        let schema = json!({
            "type": "object",
            "properties": {"command": {"type": "string"}},
            "required": ["command"]
        });

        assert_eq!(sanitize_schema(schema.clone()), schema);
    }

    #[test]
    fn sanitize_strips_root_anyof_with_required_only_branches() {
        let schema = json!({
            "type": "object",
            "properties": { "a": { "type": "string" } },
            "anyOf": [
                { "required": ["a"] },
                { "required": ["b", "c"] }
            ]
        });

        let result = sanitize_schema(schema);

        assert!(result.get("anyOf").is_none());
        assert!(result.get("properties").is_some());
    }

    #[test]
    fn sanitize_strips_anyof_with_typed_branches() {
        let schema = json!({
            "type": "object",
            "anyOf": [
                { "type": "object", "properties": { "a": { "type": "string" } } }
            ]
        });

        let result = sanitize_schema(schema);

        assert!(result.get("anyOf").is_none());
    }
}