refactor(mcp): the party_id, document_id and cash_account aliases are removed (P5)

Agent reason: one name for one thing. S4 and S6 kept the old spellings "until
P5" so an agent that learned them did not break; P5 removes them, so the
schema an agent reads has one parameter for each fact and a call cannot name
the same thing twice with different answers.

books.create_invoice takes customer and books.create_bill vendor (a record's
id, its party's id or its name; required), no party_id.
books.receive_payment and books.pay_bill take invoice or bill and
deposit_to or paid_from, no document_id or cash_account; a payment names its
document and its account or is refused saying which to pass. A number that is
one record's id and another's name is still refused, never guessed (INVARIANT
6).

The over-the-wire tests that used the old spellings now use the new
(document_id becomes invoice or bill, cash_account becomes deposit_to or
paid_from, party_id becomes customer or vendor given as the id's text); the
one test that named the alias, party_id_alias_still_works, is now
a_customer_by_id_and_by_name_is_one_record and checks the same two spellings
of a customer, by id and by name, name one record.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-mcp/src/tools/documents.rs

@@ -455,17 +455,7 @@ impl BooksServer {
     ) -> Result<Json<InvoiceOut>, String> {
         let p = params.0;
         let mut store = self.lock()?;
-        let customer = match (&p.customer, p.party_id) {
-            (Some(c), None) => c.trim().to_string(),
-            (None, Some(id)) => id.to_string(),
-            (Some(c), Some(id)) if c.trim() == id.to_string() => c.trim().to_string(),
-            (Some(_), Some(_)) => {
-                return Err("give the customer once: customer or party_id, not both".into());
-            }
-            (None, None) => {
-                return Err("give customer: a customer id, a party id or a name".into());
-            }
-        };
+        let customer = p.customer.trim().to_string();
         let customer_id = resolve_customer(&store, &customer)?;
         let date = parse_date(&p.date)?;
         let lines = document_lines(&store, p.lines)?;
@@ -606,17 +596,7 @@ impl BooksServer {
     ) -> Result<Json<BillOut>, String> {
         let p = params.0;
         let mut store = self.lock()?;
-        let vendor = match (&p.vendor, p.party_id) {
-            (Some(v), None) => v.trim().to_string(),
-            (None, Some(id)) => id.to_string(),
-            (Some(v), Some(id)) if v.trim() == id.to_string() => v.trim().to_string(),
-            (Some(_), Some(_)) => {
-                return Err("give the vendor once: vendor or party_id, not both".into());
-            }
-            (None, None) => {
-                return Err("give vendor: a vendor id, a party id or a name".into());
-            }
-        };
+        let vendor = p.vendor.trim().to_string();
         let vendor_id = resolve_vendor_arg(&store, &vendor)?;
         let date = parse_date(&p.date)?;
         let received_on = p.received_on.as_deref().map(parse_date).transpose()?;

crates/ledger-mcp/src/tools/settlements.rs

@@ -39,35 +39,17 @@ fn doc_party(ledger: &Ledger, doc: ledger_core::DocRef) -> Result<u64, String> {
     }
 }
 
-/// The one id a payment tool's single form names: `invoice`/`bill`, or
-/// the older `document_id`. Both at once is refused unless they agree.
-fn single_document(primary: Option<u64>, alias: Option<u64>, what: &str) -> Result<u64, String> {
-    match (primary, alias) {
-        (Some(a), Some(b)) if a != b => Err(format!(
-            "pass {what} or document_id, not both: {} and {b} differ",
-            a
-        )),
-        (Some(id), _) | (None, Some(id)) => Ok(id),
-        (None, None) => Err(format!(
-            "pass {what} (or an applications list): see books.documents"
-        )),
-    }
+/// The one id a payment tool's single form names: `invoice` or `bill`.
+fn single_document(primary: Option<u64>, what: &str) -> Result<u64, String> {
+    primary.ok_or_else(|| format!("pass {what} (or an applications list): see books.documents"))
 }
 
-/// The one account a payment tool's single form names: `deposit_to`/
-/// `paid_from`, or the older `cash_account`.
-fn single_account(
-    primary: &Option<String>,
-    alias: &Option<String>,
-    what: &str,
-) -> Result<String, String> {
-    match (primary, alias) {
-        (Some(a), Some(b)) if a != b => Err(format!(
-            "pass {what} or cash_account, not both: {a:?} and {b:?} differ"
-        )),
-        (Some(a), _) | (None, Some(a)) => Ok(a.clone()),
-        (None, None) => Err(format!("pass {what} (or cash_account)")),
-    }
+/// The one account a payment tool's single form names: `deposit_to` or
+/// `paid_from`.
+fn single_account(primary: &Option<String>, what: &str) -> Result<String, String> {
+    primary
+        .clone()
+        .ok_or_else(|| format!("pass {what}: the account the cash moves through"))
 }
 
 /// Every document a payment tool's parameters name, as the core takes
@@ -128,7 +110,6 @@ fn applications(
     }
     let id = single_document(
         if invoices { p.invoice } else { p.bill },
-        p.document_id,
         if invoices { "invoice" } else { "bill" },
     )?;
     let amount = p
@@ -178,7 +159,6 @@ fn settlement(
             } else {
                 &p.paid_from
             },
-            &p.cash_account,
             if invoices { "deposit_to" } else { "paid_from" },
         )?,
     )?;

crates/ledger-mcp/src/types.rs

@@ -3265,10 +3265,7 @@ pub struct CreateInvoiceParams {
     pub preview: Option<String>,
     /// The customer: a customer id, its party's id, or its name. A name
     /// that two customers answer to is refused.
-    pub customer: Option<String>,
-    /// The old spelling of `customer` (accepted until P5): a customer id.
-    #[serde(default)]
-    pub party_id: Option<u64>,
+    pub customer: String,
     /// The invoice date, YYYY-MM-DD.
     pub date: String,
     /// Its payment terms ("Net 30", "Net 15 EOM", "2/10 net 30", "Due on
@@ -3300,10 +3297,7 @@ pub struct CreateBillParams {
     pub preview: Option<String>,
     /// The vendor: a vendor id, its party's id, or its name. A name that
     /// two vendors answer to is refused.
-    pub vendor: Option<String>,
-    /// The old spelling of `vendor` (accepted until P5): a vendor id.
-    #[serde(default)]
-    pub party_id: Option<u64>,
+    pub vendor: String,
     /// The bill's date, YYYY-MM-DD.
     pub date: String,
     /// The day the bill was received, when it differs from its date.
@@ -3383,10 +3377,6 @@ pub struct PaymentParams {
     /// preview: nothing posts.
     #[serde(default)]
     pub confirmed: Option<bool>,
-    /// Invoice id (receive_payment) or bill id (pay_bill); the older name
-    /// of `invoice` / `bill`.
-    #[serde(default)]
-    pub document_id: Option<u64>,
     /// The invoice, by id (books.receive_payment).
     #[serde(default)]
     pub invoice: Option<u64>,
@@ -3399,10 +3389,6 @@ pub struct PaymentParams {
     /// applications' amounts are the cash; a discount is beside it.
     #[serde(default)]
     pub amount: Option<String>,
-    /// Cash account id or code; the older name of `deposit_to` /
-    /// `paid_from`.
-    #[serde(default)]
-    pub cash_account: Option<String>,
     /// The account the cash reaches (receive_payment): a bank or card that
     /// holds no role.
     #[serde(default)]