Brex MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: it supports pagination and user filtering, specifies what it returns ('transactions with money annotation'), and notes limitations (no posted_at_start or expand parameters). However, it doesn't mention rate limits, authentication needs, or error handling, leaving some gaps.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is efficiently structured with three sentences: the first states the core purpose, the second adds behavioral details, and the third provides critical usage notes. Every sentence adds value without redundancy, making it easy to parse and front-loaded with essential information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity (list operation with filtering and pagination), no annotations, and no output schema, the description does a good job covering key aspects like scope, behaviors, and limitations. However, it lacks details on return format structure, error cases, or authentication requirements, which could be important for a tool with multiple parameters and no output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already fully documents the three parameters (cursor, limit, user_ids). The description adds minimal value beyond the schema by mentioning 'user filtering' which aligns with user_ids, but doesn't provide additional syntax, format details, or context about the parameters. This meets the baseline for high schema coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('List settled transactions') and resource ('for all card accounts'), distinguishing it from siblings like get_cash_transactions or get_transactions by specifying it's for card accounts only. The phrase 'primary card endpoint' further clarifies its role in the API hierarchy.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit guidance on when to use alternatives: it states 'Does not support posted_at_start or expand parameters - filter client-side by posted_at_date if needed,' directing users to client-side filtering instead of expecting server-side support. This helps differentiate from potential sibling tools that might offer those parameters.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.