(bug) In-process agent runtime renames session and agent to the same single capital letter

[ashrafchowdury]

When the "In-process agent runtime" feature flag is enabled and I create a new agent:

1. My first message causes the agent to rename both the session and itself, both to the same name.
2. The assigned name is always a single capital letter — like "L" or "F" — rather than a name derived from context in my message.
3. It seems like the agent is using the same tool for both the session and agent rename, causing both to get the same name.

Expected: the session and agent should get distinct names based on understanding the conversation context, and the names should be multi-character labels, not single capital letters.

To reproduce:

1. Enable the "In-process agent runtime" feature flag in production.
2. Create a new agent.
3. Send any the first message.
4. Check session name and agent name — both are set to the same single character.

Environment: production with the "In-process agent runtime" FF enabled.

[linear-code]

AGE-4469

[bhattyuvraj22]

Hi @mmabrouk! I'd like to work on this bug, if it's available for contributors. I see it's assigned to you, so please let me know if you're already on it or would prefer to handle it yourself.

From what I read in the history (#5903, #5908), rename_session and rename_agent are separate tools, and the persona is meant to call both on a first task. So my first step is to check how the in-process runtime handles those two calls compared to the default path, and where the name value gets reduced to one character.

Plan

Reproduce locally with the "In-process agent runtime" flag enabled.
Trace the name from the model's tool call to where it's saved, for both renames, and find where it becomes a single letter.
Fix it so the session and the agent each get their own multi-character name.
Add a test that fails on the current behavior.

One question: how do I enable the "In-process agent runtime" flag in a local setup (env variable or setting)?

I'll wait for your go-ahead before opening a PR.