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 clearly indicates this is a read operation ('Retrieve') and specifies the scope of returned data, but does not mention authentication requirements, rate limits, error conditions, or whether the data is real-time vs cached. It adds value beyond the schema but lacks comprehensive behavioral context.

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 in two sentences: the first states the core purpose and key parameter, the second enumerates the returned data fields. Every element serves a clear purpose with zero redundant 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?

For a single-parameter read tool with no annotations and no output schema, the description provides adequate purpose and output scope. However, it lacks information about authentication, error handling, data freshness, or response structure details that would be helpful given the absence of structured output documentation.

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 single 'accountId' parameter. The description adds no additional parameter semantics beyond what the schema provides, such as format examples or validation rules. Baseline 3 is appropriate when the schema does all the parameter documentation work.

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 ('Retrieve detailed information'), target resource ('for a specific Brex account'), and key scope ('by account ID'). It distinguishes from sibling tools like 'get_all_accounts' by specifying retrieval for a single account rather than all accounts.

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 implies usage context by specifying 'by account ID' and listing the returned details, which helps differentiate it from tools like 'get_budget' or 'get_transactions'. However, it does not explicitly state when NOT to use this tool or name specific alternatives for different scenarios.

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