coercion error with code -32603

[simonpcouch]

Currently, seeing:

<simpleError in as.vector(x, "character"): cannot coerce type 'object' to vector of type 'character'>

It's from the session; the message is properly passed on:

TO SESSION: {"method":"tools/call","params":{"name":"btw_tool_env_describe_environment","arguments":{"intent":"Check what data frames are loaded in the current R environment"}},"jsonrpc":"2.0","id":9}

This is because btw tools now return ellmer tool results rather than strings:

btw::btw_tool_env_describe_environment()
<btw::BtwToolResult>
 @ value  : chr [1:5] "## Context" "" ...
 @ error  : NULL
 @ extra  : list()
 @ request: NULL