brain_search

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

The description discloses core behavioral traits: it performs a hybrid dense/BM25 search with RRF fusion and can be narrowed by path_prefix. However, with no annotations provided, it does not explicitly confirm read-only behavior, return ordering, or any potential side effects, leaving some burden unmet.

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 extremely concise and front-loaded: the first sentence captures the core retrieval behavior, and the second adds the only notable parameter nuance. No filler or redundant information is present.

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 relatively simple three-parameter search tool with an output schema, the description provides the essential algorithm and scope control. It remains incomplete because it does not clarify how results are ranked, when to choose this over grep, or any implicit defaults, making it adequate but not fully self-sufficient.

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 0%, so the description must compensate. It only adds meaning for path_prefix ('narrows scope') and says nothing about query semantics or how limit behaves, leaving the agent to infer those from parameter names alone.

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 indicates a technical search mechanism ('Dense + BM25 prefetch, RRF fusion') and an optional scope narrowing via path_prefix, which conveys that this is a hybrid retrieval tool over the 'brain' corpus. It does not use an explicit verb like 'searches' but the meaning is clear enough and distinguishes it from simpler grep/list operations.

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?

There is no explicit guidance on when to use brain_search versus sibling tools such as brain_grep or brain_list. 'Optional path_prefix narrows scope' offers parameter-level context but does not explain when hybrid search is preferred over alternative tools.

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