User info

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

Annotations already mark the tool as readOnly and openWorld. The description adds useful behavioral context beyond those hints: the white-branding id can be empty for most direct IBKR clients, implying the return value is not always populated. This helps the agent interpret results without contradicting the annotations.

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 only two sentences and front-loads the core action ('Return details about the logged-in IBKR user') before explaining the white-branding id. Every sentence adds meaningful context, with no filler or repetition of the schema.

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 no-parameter, read-only tool with an output schema and annotations, the description fully covers what an agent needs to know: what is returned, the meaning of the returned field, and the empty-value case. There are no obvious gaps for correct invocation or result interpretation.

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?

The input schema has zero parameters, so the baseline is 4. The description adds no parameter-specific semantics, but none are needed. It correctly focuses on the tool's output and meaning instead.

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 opens with a specific verb and resource: 'Return details about the logged-in IBKR user.' It then pinpoints the key content (white-branding id) and distinguishes it from account summaries or connection info by emphasizing the user identity and white-label context. This makes the tool's purpose unmistakable.

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 establishes clear context for use: it is for retrieving details about the logged-in IBKR user, specifically the white-branding id. It also clarifies when the value will be empty, which helps an agent decide whether this tool is relevant. It does not explicitly name alternatives, but the context is sufficient given the tool's unique role.

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