MCP tools and resources for Oda

When you connect an MCP server, DataMind Oda receives the tools and resources that server offers and can use them while it works in your chats. This page explains what Oda gets from a server, how results come back, and the rules that keep the connection trustworthy. To add and manage servers, see MCP servers; for services that sign in through the browser, see Connectors.

What a connected server gives Oda

Its tools. Every enabled server contributes its tools to the set Oda can call. Oda uses them for the tasks that fit, alongside its own tools.
Availability follows the switch. A server you disable in Settings stops contributing tools; enable it again and its tools return.
One complete set per server. Oda takes a server's tool list as a whole. When the server changes its list, the complete new set replaces the old one; old and new tools are never mixed.
A list Oda cannot accept changes nothing. If a server's list repeats a tool name, Oda rejects that list and keeps the previous set in place.
Names that stay apart. Two servers may offer a tool with the same name. Oda keeps them separate by the server they came from, and a tool keeps its name when Oda restarts.

What tool results look like

Most results from these tools read like any other tool result. When a result cannot be used as it is, Oda shows a note in its place:

Note	What it means
`[image unavailable: ...]`	The server returned an image that could not be placed in this chat. The note names the image type and the reason, for example that the chat's model does not accept images. The image itself remains available to programs that read the session.
`[audio result unsupported: ...]`	The server returned audio, which Oda does not place in a chat.
`[unsupported MCP content type: <type>]`	The result contains a kind of content Oda cannot show; the note names it.
`Resource link: <name> (<URI>)`	The result points to content held on the server. Oda can read it when the server supports resources.
`[binary resource: <count> base64 characters; available to programmatic callers]`	A resource read returned binary data. Oda shows its size instead of the bytes themselves.
`(<tool name> returned no model-visible content)`	The call finished, but the server returned nothing Oda can use.

Note

In these notes, "programmatic callers" means programs that read the session rather than people in the chat. The raw data stays out of the chat text but is not lost.

Resources: what Oda can list and read

Oda has three tools for working with server resources:

List resources on a named server.
List resource templates, the address patterns a server uses for resources it can produce.
Read a resource by its address (URI), including one expanded from a template.

Oda is told which servers it can read from, and it names one of them in every request. A server this chat cannot see is refused before anything is sent: MCP resource server "<name>" is unavailable in this agent's scope.

Long lists come in pages. Oda asks for the next page when it needs it.
Binary resources stay out of the chat. A binary read shows its size instead of its bytes: [binary resource: <count> base64 characters; available to programmatic callers].
No automatic updates. Oda is not notified when a resource changes, so it reads the resource again when it needs the current contents.
No servers, no tools. With no servers, these three tools do not appear at all.

Rules for calls and connections

Failures are shown. When a call fails, it is reported as a failure. Oda never receives a failed call as if it had succeeded.
Separate tasks are refused. Some servers offer tools that run as separate long tasks. Oda does not support that kind of call; it is refused with a message saying the tool requires task-based execution.
A size limit on server instructions. A server can send a block of guidance text with its connection. If the block is larger than Oda accepts (32,768 bytes by default), the connection is refused.
When a server needs attention. If a server will not connect or stops answering, see MCP servers: recovery and troubleshooting.

Questions, answered

How does Oda learn which tools a server offers?

When a server connects, Oda reads its tool list. When the server tells Oda the list changed, Oda reads it again, and it re-reads the list after a reconnect.

Are a server's tools available in every chat?

Yes, while the server is enabled. Oda can call them in your chats. If you disable the server in Settings, its tools leave Oda's list until you enable it again.

What happens when a server changes its tools while I work?

Oda takes the new list as a whole: a tool the server added becomes available, a tool it removed stops being called, and old and new tools are never mixed.

Two servers offer a tool with the same name. Which one does Oda use?

Both stay available. Oda keeps the two apart by the server they came from, so each call goes to the server whose tool Oda picked.

Why did an image from a server show as a line of text?

The image could not be placed in this chat. The note says why, for example that the chat's model does not accept images. The image itself remains available to programs that read the session.

Can Oda read a server's resources?

Yes, when the server offers resources. Oda lists them and reads one by its address, using only servers this chat can see; a server outside its reach is refused before anything is sent.

Do resources refresh on their own?

No. Oda is not notified when a resource changes; it reads the resource again when it needs the current contents.

Why is a tool refused with a message about task-based execution?

That tool runs as a separate long task on the server, and Oda does not support that kind of call. The server's other tools keep working.

Why did a tool call come back with no content?

The call finished, but the server returned nothing Oda can use, and the result says so. If you expected content, check that tool on the server side.