diff --git a/src/phoenix/db/migrations/versions/bc8fea3c2bc8_add_prompt_tables.py b/src/phoenix/db/migrations/versions/bc8fea3c2bc8_add_prompt_tables.py
index 0c8a135986..d3012e70de 100644
--- a/src/phoenix/db/migrations/versions/bc8fea3c2bc8_add_prompt_tables.py
+++ b/src/phoenix/db/migrations/versions/bc8fea3c2bc8_add_prompt_tables.py
@@ -48,8 +48,8 @@ def upgrade() -> None:
     op.create_table(
         "prompt_labels",
         sa.Column("id", sa.Integer, primary_key=True),
-        sa.Column("name", sa.String, nullable=False, unique=True),
-        sa.Column("description", sa.String),
+        sa.Column("name", sa.String, nullable=False, unique=True, index=True),
+        sa.Column("description", sa.String, nullable=True),
     )
 
     op.create_table(
@@ -62,8 +62,8 @@ def upgrade() -> None:
             nullable=True,
             index=True,
         ),
-        sa.Column("name", sa.String, unique=True, nullable=False),
-        sa.Column("description", sa.String),
+        sa.Column("name", sa.String, unique=True, index=True, nullable=False),
+        sa.Column("description", sa.String, nullable=True),
         sa.Column(
             "created_at",
             sa.TIMESTAMP(timezone=True),
diff --git a/src/phoenix/db/models.py b/src/phoenix/db/models.py
index 4c2197458a..52afec0764 100644
--- a/src/phoenix/db/models.py
+++ b/src/phoenix/db/models.py
@@ -800,7 +800,7 @@ class PromptLabel(Base):
     __tablename__ = "prompt_labels"
 
     id: Mapped[int] = mapped_column(primary_key=True)
-    name: Mapped[str] = mapped_column(String, unique=True, nullable=False)
+    name: Mapped[str] = mapped_column(String, unique=True, index=True, nullable=False)
     description: Mapped[Optional[str]]
 
     prompts_prompt_labels: Mapped[list["PromptPromptLabel"]] = relationship(
@@ -810,8 +810,6 @@ class PromptLabel(Base):
         uselist=True,
     )
 
-    __table_args__ = (UniqueConstraint("name"),)
-
 
 class Prompt(Base):
     __tablename__ = "prompts"
@@ -822,7 +820,7 @@ class Prompt(Base):
         index=True,
         nullable=True,
     )
-    name: Mapped[str] = mapped_column(String, unique=True, nullable=False)
+    name: Mapped[str] = mapped_column(String, unique=True, index=True, nullable=False)
     description: Mapped[Optional[str]]
     created_at: Mapped[datetime] = mapped_column(UtcTimeStamp, server_default=func.now())
     updated_at: Mapped[datetime] = mapped_column(
@@ -850,8 +848,6 @@ class Prompt(Base):
         uselist=True,
     )
 
-    __table_args__ = (UniqueConstraint("name"),)
-
 
 class PromptPromptLabel(Base):
     __tablename__ = "prompts_prompt_labels"
@@ -903,11 +899,11 @@ class PromptVersion(Base):
     )
     template: Mapped[dict[str, Any]] = mapped_column(JsonDict, nullable=False)
     invocation_parameters: Mapped[Optional[dict[str, Any]]] = mapped_column(
-        JsonDict, default=dict, nullable=True
+        JsonDict, default=None, nullable=True
     )
-    tools: Mapped[Optional[dict[str, Any]]] = mapped_column(JsonDict, default=dict, nullable=True)
+    tools: Mapped[Optional[dict[str, Any]]] = mapped_column(JsonDict, default=None, nullable=True)
     output_schema: Mapped[Optional[dict[str, Any]]] = mapped_column(
-        JsonDict, default=dict, nullable=True
+        JsonDict, default=None, nullable=True
     )
     model_provider: Mapped[str]
     model_name: Mapped[str]