Functions used in tools must have their parameters annotated with @Schema or at least the code must be compiled with the -parameters flag as a fallback. Your function tool will likely not work as expected and exit at runtime.

[vorburger]

Describe the bug

[INFO] [stdout] 2025-05-31T19:30:49.207+02:00 ERROR 403845 --- [ebServer.main()] com.google.adk.tools.FunctionTool        : Functions used in tools must have their parameters annotated with @Schema or at least the code must be compiled with the -parameters flag as a fallback. Your function tool will likely not work as expected and exit at runtime.
[INFO] [stdout] 2025-05-31T19:30:49.214+02:00 ERROR 403845 --- [ebServer.main()] com.google.adk.tools.FunctionTool        : Functions used in tools must have their parameters annotated with @Schema or at least the code must be compiled with the -parameters flag as a fallback. Your function tool will likely not work as expected and exit at runtime.

To Reproduce

Follow https://google.github.io/adk-docs/get-started/.

Also https://github.com/google/adk-docs/blob/005d3ca985942e60f9dcd03bf5fc8ed1192e479b/examples/java/cloud-run/pom.xml#L1

Expected behavior
No confusing looks errors shown when following getting start / quick guide.

Additional context

This is of course because of a missing -parameters arg to javac in the POM.

Interestingly, when I've tried to add it, it didn't seem to help.

Maybe it's a Maven problem?!

Needs a closer look.

Some day.

[shukladivyansh]

It's missing the name tag in the schema declaration. I'll send out a PR

[shukladivyansh]

google/adk-docs#380

[vorburger]

It's missing the name tag in the schema declaration. I'll send out a PR google/adk-docs#380

May I, most respectfully, disagree with this finding? That is only a workaround. And it's "ugly" - because it repeats the parameter name. What we really need to do is make it have the name of the parameter in the bytecode. Which Java can do, of course - with a compiler flag.

[shukladivyansh]

May I, most respectfully, disagree with this finding? That is only a workaround. And it's "ugly" - because it repeats the parameter name. What we really need to do is make it have the name of the parameter in the bytecode. Which Java can do, of course - with a compiler flag.

Agree on the ugly part. We discussed this a month back and the consensus was that we don't want the code to depend on some java flag twiddling. It should just work, hence this recommendation.

If the users want to use the -parameter flag, they can use that instead and skip the name tag.

I tried with this in pom.xml and it works

<build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.14.0</version>
        <configuration>
          <compilerArgs>
            <arg>-parameters</arg>
          </compilerArgs>
        </configuration>
      </plugin>
    </plugins>
  </build>

[vorburger]

@shukladivyansh This ^^^ does, of course, work great indeed; Thank You! (FYI I could swear that I had tried this earlier, and it didn't seem effective - but I guess that I probably must have just made a typo, or something. Please disregard related earlier comments; in the initial issue description.)

With that clarified, why don't we simply do google/adk-docs#381 instead of google/adk-docs#380, and call this done with that?

@glaforge FYI

[shukladivyansh]

For the reasons mentioned before (no dependency on specific java flags), i think we'd like to stick with annotations as the primary recommendation. however, if you want to mention the flag as an alternative in the docs, happy to lgtm that.

End users can easily switch between the two so they can always do that if they wish to. As a library, we just want to minimize the surprise that users face.