brain_call_tool

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

With no annotations, the description carries full responsibility for behavioral disclosure. It only says 'Call a tool by name' and does not mention potential side effects, error behavior, dynamic execution risk, or that it can invoke arbitrary tools with arbitrary consequences. This is a significant gap for an execution tool.

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?

Two sentences, zero filler, action stated first. The second sentence provides essential context (use after search_tools) without redundancy. Excellent front-loading.

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 simple 2-parameter tool, the description covers the core action and usage context. However, without an output schema or annotations, it omits return value behavior and error handling, which an agent might need when invoking arbitrary tools. It is adequate but not comprehensive.

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 coverage is 100%, so the schema already documents both parameters. The description adds marginal value by linking parameters to 'given arguments' from search_tools, but does not enrich semantics beyond the schema. Baseline 3 is appropriate.

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 a specific verb ('Call') and resource ('a tool by name with the given arguments'), and differentiates itself from discovery tools by positioning it as the execution step after search_tools. This makes it unambiguous against siblings like brain_find_tool.

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 phrase 'Use this to execute tools discovered via search_tools' gives clear context of when to invoke it (after discovery) and implies it is not for searching. It does not explicitly exclude session-management siblings, but the usage context is sufficient for a generic dispatcher.

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