refactor(mcp): centralize meta-function prefix predicates and fix list_tools pagination

Implements T1 of plans/mcp-resources-prompts-design.md (§4.1, §4.6):

- Replace list_tools(None) with cursor-following list_all_tools() at the
  three call sites (start_server catalog build, catalog_items, describe)
  so paginating servers no longer silently lose tools past page one.
- Add MCP_READ/MCP_PROMPT prefix constants (declared nowhere yet; wired
  in T4/T7) plus centralized helpers MCP_META_FUNCTION_PREFIXES,
  is_mcp_meta_function, and mcp_meta_function_names.
- Mechanically replace every hand-rolled 3-prefix starts_with triple
  (partition in eval_tool_calls, 3 exclusion triples in
  select_enabled_functions, 3 inclusion triples + per-server name
  construction in select_enabled_mcp_servers) with the helpers,
  preserving the existing lax starts_with matching semantics and the
  mcp_invoke_* enablement sentinel (sentinel moves to search in T5).
- Behavior-neutral: dispatch chains keep their 3 arms, emission stays
  at exactly 3 meta-functions per server, existing tests unmodified.
- Add unit tests: helper classification, prefix-soundness property,
  lax-matching pin, ordered candidate-name construction.
This commit is contained in:
2026-08-25 11:37:41 -06:00
parent 7caa24d090
commit 01ada1da18
4 changed files with 92 additions and 74 deletions
+10 -59
View File
@@ -23,8 +23,8 @@ use crate::function::{
user_interaction::USER_FUNCTION_PREFIX,
};
use crate::mcp::{
MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX, MCP_INVOKE_META_FUNCTION_NAME_PREFIX,
MCP_SEARCH_META_FUNCTION_NAME_PREFIX, McpAuthReason, McpAuthRequired, is_auth_required_error,
MCP_INVOKE_META_FUNCTION_NAME_PREFIX, McpAuthReason, McpAuthRequired, is_auth_required_error,
is_mcp_meta_function, mcp_meta_function_names,
};
use crate::rag::Rag;
use crate::supervisor::Supervisor;
@@ -2011,11 +2011,7 @@ impl RequestContext {
.functions
.declarations()
.iter()
.filter(|v| {
!v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| !is_mcp_meta_function(&v.name))
.map(|v| v.name.to_string())
.collect();
@@ -2025,11 +2021,7 @@ impl RequestContext {
.functions()
.declarations()
.iter()
.filter(|v| {
!v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| !is_mcp_meta_function(&v.name))
.map(|v| v.name.to_string()),
);
}
@@ -2102,11 +2094,7 @@ impl RequestContext {
.declarations()
.to_vec()
.into_iter()
.filter(|v| {
!v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
&& !v.name.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| !is_mcp_meta_function(&v.name))
.collect();
if let Some(ref tool_names) = role_filter {
@@ -2155,11 +2143,7 @@ impl RequestContext {
.functions
.declarations()
.iter()
.filter(|v| {
v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
|| v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
|| v.name.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| is_mcp_meta_function(&v.name))
.map(|v| v.name.to_string())
.collect();
if let Some(agent) = &self.agent {
@@ -2168,12 +2152,7 @@ impl RequestContext {
.functions()
.declarations()
.iter()
.filter(|v| {
v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
|| v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
|| v.name
.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| is_mcp_meta_function(&v.name))
.map(|v| v.name.to_string()),
);
}
@@ -2190,39 +2169,15 @@ impl RequestContext {
let item_invoke_name =
format!("{}_{item}", MCP_INVOKE_META_FUNCTION_NAME_PREFIX);
let item_search_name =
format!("{}_{item}", MCP_SEARCH_META_FUNCTION_NAME_PREFIX);
let item_describe_name =
format!("{}_{item}", MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX);
if let Some(values) = app.mapping_mcp_servers.get(item) {
server_names.extend(
values
.split(',')
.flat_map(|v| {
vec![
format!(
"{}_{}",
MCP_INVOKE_META_FUNCTION_NAME_PREFIX,
v.to_string()
),
format!(
"{}_{}",
MCP_SEARCH_META_FUNCTION_NAME_PREFIX,
v.to_string()
),
format!(
"{}_{}",
MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX,
v.to_string()
),
]
})
.flat_map(mcp_meta_function_names)
.filter(|v| mcp_declaration_names.contains(v)),
)
} else if mcp_declaration_names.contains(&item_invoke_name) {
server_names.insert(item_invoke_name);
server_names.insert(item_search_name);
server_names.insert(item_describe_name);
server_names.extend(mcp_meta_function_names(item));
}
}
}
@@ -2251,11 +2206,7 @@ impl RequestContext {
.declarations()
.to_vec()
.into_iter()
.filter(|v| {
v.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
|| v.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
|| v.name.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
})
.filter(|v| is_mcp_meta_function(&v.name))
.collect();
if let Some(ref server_names) = role_filter {
+3 -4
View File
@@ -63,10 +63,10 @@ impl McpRuntime {
.get(server)
.cloned()
.with_context(|| format!("{server} MCP server not found in runtime"))?;
let tools = server_handle.list_tools(None).await?;
let tools = server_handle.list_all_tools().await?;
let mut items = HashMap::new();
for tool in tools.tools {
for tool in tools {
let item = CatalogItem {
name: tool.name.to_string(),
server: server.to_string(),
@@ -110,9 +110,8 @@ impl McpRuntime {
.with_context(|| format!("{server} MCP server not found in runtime"))?;
let tool_schema = server_handle
.list_tools(None)
.list_all_tools()
.await?
.tools
.into_iter()
.find(|item| item.name == tool)
.ok_or_else(|| anyhow!("{tool} not found in {server} MCP server catalog"))?
+9 -9
View File
@@ -16,7 +16,7 @@ use crate::config::ensure_parent_exists;
use crate::config::paths;
use crate::mcp::{
MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX, MCP_INVOKE_META_FUNCTION_NAME_PREFIX,
MCP_SEARCH_META_FUNCTION_NAME_PREFIX, McpServersConfig,
MCP_SEARCH_META_FUNCTION_NAME_PREFIX, McpServersConfig, is_mcp_meta_function,
};
use crate::parsers::{bash, python, typescript};
use anyhow::{Context, Result, anyhow, bail};
@@ -284,14 +284,9 @@ pub async fn eval_tool_calls(
}
}
let (mcp_calls, sequential_calls): (Vec<_>, Vec<_>) =
to_execute.into_iter().partition(|(_, call)| {
call.name.starts_with(MCP_INVOKE_META_FUNCTION_NAME_PREFIX)
|| call.name.starts_with(MCP_SEARCH_META_FUNCTION_NAME_PREFIX)
|| call
.name
.starts_with(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX)
});
let (mcp_calls, sequential_calls): (Vec<_>, Vec<_>) = to_execute
.into_iter()
.partition(|(_, call)| is_mcp_meta_function(&call.name));
if !mcp_calls.is_empty() {
let ctx_ref: &RequestContext = ctx;
@@ -2128,6 +2123,11 @@ mod tests {
assert_eq!(MCP_INVOKE_META_FUNCTION_NAME_PREFIX, "mcp_invoke");
assert_eq!(MCP_SEARCH_META_FUNCTION_NAME_PREFIX, "mcp_search");
assert_eq!(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX, "mcp_describe");
assert_eq!(crate::mcp::MCP_READ_META_FUNCTION_NAME_PREFIX, "mcp_read");
assert_eq!(
crate::mcp::MCP_PROMPT_META_FUNCTION_NAME_PREFIX,
"mcp_prompt"
);
}
#[test]
+70 -2
View File
@@ -34,6 +34,29 @@ use tokio::process::Command;
pub const MCP_INVOKE_META_FUNCTION_NAME_PREFIX: &str = "mcp_invoke";
pub const MCP_SEARCH_META_FUNCTION_NAME_PREFIX: &str = "mcp_search";
pub const MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX: &str = "mcp_describe";
pub const MCP_READ_META_FUNCTION_NAME_PREFIX: &str = "mcp_read";
pub const MCP_PROMPT_META_FUNCTION_NAME_PREFIX: &str = "mcp_prompt";
pub const MCP_META_FUNCTION_PREFIXES: [&str; 5] = [
MCP_INVOKE_META_FUNCTION_NAME_PREFIX,
MCP_SEARCH_META_FUNCTION_NAME_PREFIX,
MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX,
MCP_READ_META_FUNCTION_NAME_PREFIX,
MCP_PROMPT_META_FUNCTION_NAME_PREFIX,
];
pub fn is_mcp_meta_function(name: &str) -> bool {
MCP_META_FUNCTION_PREFIXES
.iter()
.any(|prefix| name.starts_with(prefix))
}
pub fn mcp_meta_function_names(server: &str) -> Vec<String> {
MCP_META_FUNCTION_PREFIXES
.iter()
.map(|prefix| format!("{prefix}_{server}"))
.collect()
}
pub type ConnectedServer = RunningService<RoleClient, ()>;
@@ -347,11 +370,11 @@ impl McpRegistry {
Err(e) => return Err(e),
};
let tools = service.list_tools(None).await?;
let tools = service.list_all_tools().await?;
debug!("Available tools for MCP server {id}: {tools:?}");
let mut items_vec = Vec::new();
for t in tools.tools {
for t in tools {
let name = t.name.to_string();
let description = t.description.unwrap_or_default().to_string();
items_vec.push(CatalogItem {
@@ -1185,6 +1208,51 @@ mod tests {
assert_eq!(MCP_INVOKE_META_FUNCTION_NAME_PREFIX, "mcp_invoke");
assert_eq!(MCP_SEARCH_META_FUNCTION_NAME_PREFIX, "mcp_search");
assert_eq!(MCP_DESCRIBE_META_FUNCTION_NAME_PREFIX, "mcp_describe");
assert_eq!(MCP_READ_META_FUNCTION_NAME_PREFIX, "mcp_read");
assert_eq!(MCP_PROMPT_META_FUNCTION_NAME_PREFIX, "mcp_prompt");
}
#[test]
fn is_mcp_meta_function_classifies_names() {
assert!(is_mcp_meta_function("mcp_invoke_github"));
assert!(is_mcp_meta_function("mcp_search_github"));
assert!(is_mcp_meta_function("mcp_describe_github"));
assert!(is_mcp_meta_function("mcp_read_github"));
assert!(is_mcp_meta_function("mcp_prompt_github"));
assert!(!is_mcp_meta_function("mcp_gateway_tool"));
assert!(!is_mcp_meta_function("fs_read"));
assert!(!is_mcp_meta_function(""));
assert!(!is_mcp_meta_function("mcp_"));
}
#[test]
fn meta_function_prefixes_are_not_prefixes_of_each_other() {
for (i, a) in MCP_META_FUNCTION_PREFIXES.iter().enumerate() {
for (j, b) in MCP_META_FUNCTION_PREFIXES.iter().enumerate() {
if i != j {
assert!(!b.starts_with(a), "{a} is a prefix of {b}");
}
}
}
}
#[test]
fn is_mcp_meta_function_preserves_lax_prefix_matching() {
assert!(is_mcp_meta_function("mcp_invoker_x"));
}
#[test]
fn mcp_meta_function_names_returns_all_prefixes_in_order() {
assert_eq!(
mcp_meta_function_names("github"),
vec![
"mcp_invoke_github",
"mcp_search_github",
"mcp_describe_github",
"mcp_read_github",
"mcp_prompt_github",
]
);
}
#[test]