Table of contents

As you build an enterprise search platform, you’ll have two options for implementing it.
You can store and index the data (i.e., perform syncs). This involves copying content from each source into your own search index on a schedule.
And you can use the Model Context Protocol (MCP), or a live connection, which requires calling the source system’s API every time a user searches.
The two methods solve different problems. A stored index is extremely fast and supports rich ranking and analytics; while MCP results are always current but are limited by the source API, network latency, and rate limits.
We’ll further explore the pitfalls of MCP for enterprise search, the situations that still call for it, and when (and why) syncs often work better.
While MCP can provide real-time data, it faces multiple structural challenges that make it slower and less reliable than pre-synced data.
Let’s review MCP’s drawbacks in several areas.
Semantic search, which aims to understand the intent of a user’s search (versus string-matching), is now a standard expectation for enterprise search.
MCP can’t adopt it because the APIs that support search will only support exact or fuzzy string-matching. In addition, without full syncs, you won’t be able to generate and update embeddings in real time because of rate limits and cost constraints.
For example, if a user searches “company policy vocation,” MCP would simply correct the typo and return a “company policy vacation” document. Since it won’t surface and reference information from related documents, the user’s question will likely remain unanswered, forcing them to run additional searches or ask colleagues for help.
You would expect that MCP outperforms syncs here, but the reality plays out differently.
If you’re using MCP to search for the “Q4 revenue forecast” in SharePoint, for example, each /search/query could return 120 matches in ~500 ms. However, each file then requires a separate download (~400 ms each, 10 at a time due to rate limits). This can bring the total sync time to ~25–30 seconds before processing even starts.
In short, MCP latency compounds with every file, while pre-synced data delivers instant results regardless of dataset size.
If you’re making complex MCP searches for Box, you can quickly hit the 100K monthly request cap. And with the “uncapped spend” option, overages can generate unexpected charges for customers, which is impossible with pre-synced data.
Similarly, SharePoint has a rate limit of 3K requests per user per 5 minutes, but practical limits are often about 1,800 to 2,100 requests. A few large MCP searches can hit that ceiling fast, throttling performance. Pre-sync avoids consuming limits on each users’ individual queries and allows you to optimize the limit.
These are just a few examples. There are countless others that make MCP impractical for enterprise search at scale.
Despite its issues, MCP can still be useful for enterprise search.
Here are scenarios that call for MCP and others that call for syncs.
Since these queries can be more wide ranging, we broke them down by job titles.
To help you pick the right approach for the queries your enterprise search would support, you can also reference this table:
Building sync connectors in house means learning dozens of auth flows, pagination schemes, and edge cases.
Merge handles that for you by providing:
{{this-blog-only-cta}}
Learn how Mistral AI, Guru, Lattice and other leading AI companies use Merge to power semantic enterprise search in their products.