The Server URL and Header fields render a transparent input under a
formatted overlay div for env-var highlighting. The overlay used
font-medium/font-sans but the real input didn't, so glyph widths
diverged and the native caret drifted from the visible text as you
typed.

The MCP dynamic-args dropdown stringifies enum members for its
labels/values. Now that the tool schema contract accepts
non-primitive enum members (object/array), routing those through the
dropdown would collapse distinct values to "[object Object]" and
submit that string as the tool argument. Gate the dropdown on
primitive-only enums; non-primitive enums fall through to the
existing type-based branching (the JSON long-input editor for
object/array types), which round-trips arbitrary JSON correctly.

…type

isPrimitiveEnum() correctly excluded object/array enum members from
the dropdown, but the fallback only reached the long-input JSON
editor when paramSchema.type was 'array'. An object-typed (or
untyped) param with a non-primitive enum fell through to the default
short-input, which stringifies via toString() and drops the
enum-membership guarantee entirely. Any non-primitive enum now routes
straight to long-input, independent of the declared type.

…nput editor

The long-input JSON editor received value={value || ''} unconditionally,
so an argument already holding a parsed object/array (loaded from the
block's JSON arguments field) rendered as "[object Object]" or a
comma-joined list instead of valid JSON, and saving would overwrite the
real value with that mangled text. Serialize non-string values with
JSON.stringify before display; onChange still stores the raw text the
user edits, unchanged.

The long-input editor's onChange always stored the raw typed text, so
a param whose schema requires an object/array/non-primitive-enum value
(e.g. entering {"mode":"strict"}) was persisted as a string, not the
actual JSON value — the MCP tool call could receive the wrong type.
requiresJsonValue() identifies these schemas; onChange now parses the
edited text back into the real value once it's valid JSON, falling
back to the raw string mid-edit so the controlled textarea keeps
reflecting in-progress keystrokes.