diff --git a/mcp-server.cabal b/mcp-server.cabal
--- a/mcp-server.cabal
+++ b/mcp-server.cabal
@@ -15,7 +15,7 @@
 -- PVP summary:     +-+------- breaking API changes
 --                  | | +----- non-breaking API additions
 --                  | | | +--- code changes with no API change
-version: 0.1.0.3
+version: 0.1.0.4
 -- A short (one-line) description of the package.
 synopsis: Library for building Model Context Protocol (MCP) servers
 -- A longer description of the package.
diff --git a/src/MCP/Server/Derive.hs b/src/MCP/Server/Derive.hs
--- a/src/MCP/Server/Derive.hs
+++ b/src/MCP/Server/Derive.hs
@@ -12,9 +12,20 @@
 import qualified Data.Text           as T
 import           Language.Haskell.TH
 import           Text.Read           (readMaybe)
+import qualified Data.Char           as Char
 
 import           MCP.Server.Types
 
+-- Helper function to convert PascalCase/camelCase to snake_case
+toSnakeCase :: String -> String
+toSnakeCase [] = []
+toSnakeCase (x:xs) = Char.toLower x : go xs
+  where
+    go [] = []
+    go (c:cs)
+      | Char.isUpper c = '_' : Char.toLower c : go cs
+      | otherwise = c : go cs
+
 -- Helper function to convert Clause to Match
 clauseToMatch :: Clause -> Match
 clauseToMatch (Clause ps b ds) = Match (case ps of [p] -> p; _ -> TupP ps) b ds
@@ -49,14 +60,14 @@
 
 mkPromptDef :: Con -> Q Exp
 mkPromptDef (NormalC name []) = do
-  let promptName = T.toLower . T.pack . nameBase $ name
+  let promptName = T.pack . toSnakeCase . nameBase $ name
   [| PromptDefinition
       { promptDefinitionName = $(litE $ stringL $ T.unpack promptName)
       , promptDefinitionDescription = $(litE $ stringL $ "Handle " ++ nameBase name)
       , promptDefinitionArguments = []
       } |]
 mkPromptDef (RecC name fields) = do
-  let promptName = T.toLower . T.pack . nameBase $ name
+  let promptName = T.pack . toSnakeCase . nameBase $ name
   args <- sequence $ map mkArgDef fields
   [| PromptDefinition
       { promptDefinitionName = $(litE $ stringL $ T.unpack promptName)
@@ -78,14 +89,14 @@
 
 mkPromptCase :: Name -> Con -> Q Clause
 mkPromptCase handlerName (NormalC name []) = do
-  let promptName = T.toLower . T.pack . nameBase $ name
+  let promptName = T.pack . toSnakeCase . nameBase $ name
   clause [litP $ stringL $ T.unpack promptName]
     (normalB [| do
         content <- $(varE handlerName) $(conE name)
         pure $ Right content |])
     []
 mkPromptCase handlerName (RecC name fields) = do
-  let promptName = T.toLower . T.pack . nameBase $ name
+  let promptName = T.pack . toSnakeCase . nameBase $ name
   body <- mkRecordCase name handlerName fields
   clause [litP $ stringL $ T.unpack promptName] (normalB (return body)) []
 mkPromptCase _ _ = fail "Unsupported constructor type"
@@ -191,7 +202,7 @@
 
 mkResourceDef :: Con -> Q Exp
 mkResourceDef (NormalC name []) = do
-  let resourceName = T.toLower . T.pack . nameBase $ name
+  let resourceName = T.pack . toSnakeCase . nameBase $ name
   let resourceURI = "resource://" <> T.unpack resourceName
   [| ResourceDefinition
       { resourceDefinitionURI = $(litE $ stringL resourceURI)
@@ -203,7 +214,7 @@
 
 mkResourceCase :: Name -> Con -> Q Clause
 mkResourceCase handlerName (NormalC name []) = do
-  let resourceName = T.toLower . T.pack . nameBase $ name
+  let resourceName = T.pack . toSnakeCase . nameBase $ name
   let resourceURI = "resource://" <> T.unpack resourceName
   clause [litP $ stringL resourceURI]
     (normalB [| Right <$> $(varE handlerName) $(conE name) |])
@@ -239,7 +250,7 @@
 
 mkToolDef :: Con -> Q Exp
 mkToolDef (NormalC name []) = do
-  let toolName = T.toLower . T.pack . nameBase $ name
+  let toolName = T.pack . toSnakeCase . nameBase $ name
   [| ToolDefinition
       { toolDefinitionName = $(litE $ stringL $ T.unpack toolName)
       , toolDefinitionDescription = $(litE $ stringL $ nameBase name)
@@ -249,7 +260,7 @@
           }
       } |]
 mkToolDef (RecC name fields) = do
-  let toolName = T.toLower . T.pack . nameBase $ name
+  let toolName = T.pack . toSnakeCase . nameBase $ name
   props <- sequence $ map mkProperty fields
   requiredFields <- return $ map (\(fieldName, _, fieldType) ->
     let isOptional = case fieldType of
@@ -293,14 +304,14 @@
 
 mkToolCase :: Name -> Con -> Q Clause
 mkToolCase handlerName (NormalC name []) = do
-  let toolName = T.toLower . T.pack . nameBase $ name
+  let toolName = T.pack . toSnakeCase . nameBase $ name
   clause [litP $ stringL $ T.unpack toolName]
     (normalB [| do
         content <- $(varE handlerName) $(conE name)
         pure $ Right content |])
     []
 mkToolCase handlerName (RecC name fields) = do
-  let toolName = T.toLower . T.pack . nameBase $ name
+  let toolName = T.pack . toSnakeCase . nameBase $ name
   body <- mkRecordCase name handlerName fields
   clause [litP $ stringL $ T.unpack toolName] (normalB (return body)) []
 mkToolCase _ _ = fail "Unsupported constructor type for tools"
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -148,25 +148,25 @@
     let (_, getHandler) = testPromptHandlers
     
     -- Test simple prompt
-    result1 <- getHandler "simpleprompt" [("message", "hello")]
+    result1 <- getHandler "simple_prompt" [("message", "hello")]
     let test1 = case result1 of
             Right (ContentText content) -> content == "Simple prompt: hello"
             _ -> False
     
     -- Test complex prompt with multiple types
-    result2 <- getHandler "complexprompt" [("title", "urgent task"), ("priority", "5"), ("urgent", "true")]
+    result2 <- getHandler "complex_prompt" [("title", "urgent task"), ("priority", "5"), ("urgent", "true")]
     let test2 = case result2 of
             Right (ContentText content) -> content == "Complex prompt: urgent task (priority=5, urgent=True)"
             _ -> False
     
     -- Test optional prompt with missing optional field
-    result3 <- getHandler "optionalprompt" [("required", "test")]
+    result3 <- getHandler "optional_prompt" [("required", "test")]
     let test3 = case result3 of
             Right (ContentText content) -> content == "Optional prompt: test"
             _ -> False
     
     -- Test optional prompt with optional field present
-    result4 <- getHandler "optionalprompt" [("required", "test"), ("optional", "42")]
+    result4 <- getHandler "optional_prompt" [("required", "test"), ("optional", "42")]
     let test4 = case result4 of
             Right (ContentText content) -> content == "Optional prompt: test optional=42"
             _ -> False
@@ -178,7 +178,7 @@
     let (_, readHandler) = testResourceHandlers
     
     -- Test simple resource
-    case parseURI "resource://configfile" of
+    case parseURI "resource://config_file" of
         Just uri1 -> do
             result1 <- readHandler uri1
             let test1 = case result1 of
@@ -186,7 +186,7 @@
                     _ -> False
             
             -- Test parameterized resource (this would need to match actual schema)
-            case parseURI "resource://databaseconnection" of
+            case parseURI "resource://database_connection" of
                 Just uri2 -> do
                     result2 <- readHandler uri2
                     let test2 = case result2 of