MCP Tool Limits: Diagnose and Reduce the Catalog
A large tool catalog can exceed a client or model’s supported limits, or add discovery overhead. Zero tools is not enough to diagnose a cap. Start with No tools appearing if the connection or authentication has not been verified.
EMCP’s catalog contains up to 526 tools. What a site exposes depends on installed integrations, tier, enabled tools and configuration. Client behavior also varies by version, model and other connected servers; this guide does not promise a universal maximum or an unlimited client.
Check the evidence first
Section titled “Check the evidence first”| Observation | What it tells you |
|---|---|
| Authentication or initialization fails | Resolve that failure before investigating catalog size. |
| Independent discovery succeeds but the usual client fails | Compare identity, transport, client configuration and logs; a cap is one possible cause. |
| Client explicitly reports too many tools/functions | Record the exact limit, client/model version and whether other servers count toward it. |
| Compact mode works but the full catalog fails | The failure is associated with catalog size or handling. It does not prove a specific numeric cap. |
| One tool call is denied after discovery | Investigate that tool’s permissions, enabled setting and inputs. |
Try Compact tool mode
Section titled “Try Compact tool mode”- Record the failing client/version, model, observed count and error. Keep the same endpoint and account for the comparison.
- In WordPress, open EMCP Tools → Tools, switch on the Compact tool mode card (“For clients with tool limits”), and choose Save changes in the save bar that appears at the bottom. Coordinate this site-wide change with other connected users.
- Reconnect your client so it reads the new catalog. If necessary, start a fresh conversation.
- Look for
list-tools,get-tool-schemaandcall-tool(possibly prefixed by the server name). Proxy routing tools may appear in addition. - Ask the agent to discover a read-only page-listing operation, fetch its schema and list page titles, IDs and statuses. Do not test with a write.
Compact mode advertises three dispatcher entries instead of each underlying operation. It reduces the advertised catalog; it does not guarantee compatibility with every client. Full behavior is explained in Compact mode.
Interpret the comparison
Section titled “Interpret the comparison”If Compact mode works, keep it enabled if it suits your workflow. A repeatable full-catalog failure and compact-catalog success is useful evidence of a discovery, schema-size or tool-budget problem. Check the client log or current vendor documentation before calling it a confirmed count cap.
If both fail, return to connection diagnosis. If both discover tools but one operation fails, inspect that operation rather than changing the entire catalog.
You can also reduce enabled tools to the operations your project needs. On Tools, each platform tab (your selected builder, WordPress, Plugins, Themes, Gutenberg, EMCP Modules) and each category section shows enabled / total counts, sections have Enable and Disable buttons, and Bulk Actions offers Disable all visible for the current tab and filters. Reset to defaults in the same menu returns every toggle to its default; nothing is written until you choose Save changes. Selecting only the builder you use on EMCP Tools → Page Builders also keeps other builders’ tools out of the catalog. Avoid enabling everything to troubleshoot. Changes on Tools apply across clients, and client-side hiding is not a replacement for WordPress permission checks.
Permissions still apply
Section titled “Permissions still apply”The dispatcher refuses unknown or disabled tools and delegates execution to the target tool’s permission check. Compact mode does not grant additional privileges. Sensitive operations may need explicit enablement, and permissions differ by tool. See tool controls and secure WordPress AI setup.
If you report a failure, include both test outcomes, client/model versions, catalog counts, other connected servers and a redacted error. Never include credentials or session headers.