# MCP: tool changes are trust changes

https://thiago.limaesilvatecnologia.com.br/en/artigos/mcp-tool-change/

Published: 2026-09-12

An agent's tool catalog needs governance.

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Reading-path month: May 2026

Collection published on September 12, 2026. Months organize the reading path; they are not earlier publication dates.

A short architecture article. The technical reference supports the topic; hypothetical scenarios and assessment proposals are editorial analysis, not accounts of personal implementations.

## The architecture decision

Connecting a tool server changes what an agent can do. Later catalog changes can alter that capability without changing the model.

## Practical application

Editorial proposal: record origin, purpose and operations for each accepted tool. In a hypothetical integration, distinguish file reading from record modification. Define how the team detects behavior or scope changes.

## How to verify

Exercise tool removal and parameter changes in testing. Check that agents and controls remain consistent with approved configuration. Aim for a reviewable capability inventory with owners and an update procedure.

## Sources

- [OWASP — MCP Security Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/MCP_Security_Cheat_Sheet.html). Accessed: 2026-09-12.

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