The server with 1,649 tools
The largest tool surface we have measured holds 1,649 tools. That is not a feature. Here is what a bloated tool list costs the agent trying to use it.
Somewhere in the catalogue sits a server offering 1,649 tools in a single list. It is the biggest tool surface we have recorded. It is also, for most agents, unusable.
Why size hurts
An agent picking a tool does not read your list the way a developer reads documentation. It gets the names and descriptions in its context window and has to choose in one shot. Every extra tool is another near-miss to be confused by.
- Long lists eat the context budget before the task even starts.
- Similar names collide: create_item, add_item, new_item, item_create.
- A wrong pick is silent — the agent gets a plausible answer from the wrong tool.
The shape that works
The servers that score well on agent readability are not the ones with the most tools. They are the ones where a name says what it does, a description says when to use it and the parameters say what is required. Fewer, sharper tools beat a catalogue.
A quick test
Read your own tool list the way a model would: names and one-line descriptions, nothing else, no source code. If you cannot pick the right tool for a simple task in a few seconds, neither can the agent.
Check your server’s readability score