5.8 KiB
Guided MCP prompts and completion
REA exposes six provider-neutral investigation workflows through the MCP
prompts capability. They complement the generated tool catalog; they do not add, remove, or
invoke tools by themselves.
Prompt inventory
| Prompt | Purpose |
|---|---|
investigate_feature |
Trace a feature from discovery into bounded function evidence. |
compare_application_versions |
Compare two shipped artifacts, with optional static and runtime follow-up. |
verify_reconstruction |
Evaluate a finite reconstruction specification against retained comparison Evidence. |
trace_crash |
Correlate a crash symptom with static paths and optional process capture evidence. |
audit_residual_unknowns |
Audit current residual-unknown heads and evidence-qualified resolution. |
prepare_bounded_process_capture |
Design an approval-gated, bounded process experiment before execution. |
Every rendered prompt provides optional starting points using current REA tool names. Agents can call tools directly, skip irrelevant suggestions, and inspect provider or target state only when it helps answer the request or a tool requires it. The prompts also ask agents to keep observations, inferences, and unknowns distinct. Requested prompt arguments and completion choices are rendered as untrusted selection data, not instructions or authorization.
For target paths in compare_application_versions, the prompt suggests
opening each target before calling inspect_artifact; inspection operates on
the active target and returns the graph and findings together inline.
Use standard MCP discovery and retrieval:
{ "method": "prompts/list", "params": {} }
{
"method": "prompts/get",
"params": {
"name": "investigate_feature",
"arguments": {
"feature": "offline search",
"document": "Notes"
}
}
}
The server advertises listChanged: true. Updating a registered guided prompt
emits notifications/prompts/list_changed, allowing clients to refresh their
cached prompt catalog.
Session-aware completion
MCP completion/complete completes guided-prompt arguments; it does not define
completion for arbitrary tool-call arguments. REA attaches completion to
optional prompt arguments that feed later tool selection.
{
"method": "completion/complete",
"params": {
"ref": {
"type": "ref/prompt",
"name": "investigate_feature"
},
"argument": {
"name": "procedure",
"value": "0x10"
},
"context": {
"arguments": {
"document": "Notes"
}
}
}
}
Completion sources are live projections of the current session:
| Argument family | Source and filtering |
|---|---|
| Document | Current provider list_documents result. |
| Procedure | The complete list_procedures inventory; all procedure addresses and uniquely named procedures are offered. Optional document context is forwarded. |
| Provider | auto plus sorted deep candidates from the current binary session; target-free completion does not start them. |
| Evidence | Evidence IDs retained in the current session ledger. |
| Process capture | Evidence IDs whose operation and validated result identify process capture. |
| Artifact manifest | Manifest IDs from schema-valid retained artifact inventories. |
| Artifact occurrence | Occurrence IDs present in schema-valid retained artifact inventory pages. |
| Residual unknown | Current non-resolved unknown heads only. |
Suggestions are Unicode-normalized, case-insensitive prefix matches. The server deduplicates them and sorts by code point for deterministic results. Procedure completion derives candidates from the complete inventory, so a name is offered only when it identifies one address in that inventory. Completion returns all matching values; it does not expose paging controls.
Lifecycle and safety
Completion has no cache in REA. Opening or switching a target changes document and procedure suggestions on the next request. Closing the binary clears its Evidence ledger and residual-unknown registry, so identifiers from the closed session are no longer suggested. Provider errors, unsupported operations, and malformed provider output produce an empty completion list rather than an unverified identifier.
Suggestions never grant permission. In particular, selecting an artifact occurrence does not authorize extraction, selecting an unknown does not authorize mutation, and selecting a prior capture does not authorize process execution. The corresponding tools retain their existing approval, policy, effect, and validation boundaries.