---
id: CMP-9
family: RT-CMP
level: extended
profiles: [runtime]
posture: normative-target
added: "1.0"
changed: "1.0"
source: https://flowdrop.io/spec/rules/rt-cmp/cmp-9
specification: FlowDrop Workflow Specification 1.0-draft
licence: CC BY 4.0
---

# CMP-9 — Tool names are unique per consumer, checked at compile time

*RT-CMP (Part II) · level: extended · profiles: runtime · added in 1.0*

## The rule

> **Normative.** This is the rule.
>
> 1. For each node that consumes tools, the names of the tools wired to it must be unique across the flattened set of leaf tools it will see.
>
> 2. A collision refuses compilation.
>
> 3. Passthrough tools are exempt from this check and are checked at the consumer instead.


## What it means

Two things about the check are easy to guess wrong. First, it is not scoped
to the tools wired straight onto a node: the flattened set includes every
tool reachable through any number of passthrough hops, so a collision two
hops away is refused exactly as one on a direct wire would be, and a
passthrough node's own name plays no part in it — only the leaf tools it
forwards count, checked where they finally land. Second, the check is scoped
to one node's own view, not to the workflow as a whole: the same name landing
on two different nodes is not a collision at all.

## Example

Two tools, reached by an agent through a passthrough box, whose labels look
different but resolve to the same name:

```json title="Two tools reaching one node through a box" verdict="refused"
{
  "nodes": [
    { "id": "tool_a", "type": "http_request", "data": { "label": "Web Search" } },
    { "id": "tool_b", "type": "http_request", "data": { "label": "web-search" } },
    { "id": "box_1", "type": "toolbox", "data": { "label": "My Tools" } }
  ],
  "edges": [
    { "source": "tool_a", "target": "box_1", "data": { "edgeType": "tool_availability" } },
    { "source": "tool_b", "target": "box_1", "data": { "edgeType": "tool_availability" } },
    { "source": "box_1", "target": "agent_1", "data": { "edgeType": "tool_availability" } }
  ]
}
```

The same pair of labels causes no trouble at all once they sit on two
different nodes instead of one:

```json title="The same tool name at two different consumers" verdict="accepted"
{
  "nodes": [
    { "id": "tool_a", "type": "http_request", "data": { "label": "Search" } },
    { "id": "tool_b", "type": "http_request", "data": { "label": "Search" } }
  ],
  "edges": [
    { "source": "tool_a", "target": "agent_1", "data": { "edgeType": "tool_availability" } },
    { "source": "tool_b", "target": "agent_2", "data": { "edgeType": "tool_availability" } }
  ]
}
```

## Related rules

- Names: CMP-10
- Referenced by: CMP-1, CMP-10

---

Rule identifiers are permanent and are never renumbered. This specification carries
no implementation status: each implementation publishes its own standing against
these rules. Licensed CC BY 4.0.