list_regions

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

With no annotations, the description carries full burden. It reveals the tool returns voxel counts and centroids, and imposes a 200-row cap. It does not mention error states or permissions, but the core behavior is transparent.

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 a compact two-paragraph docstring with clear Args section. Every sentence adds value, no repetition or fluff.

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?

Despite no output schema, the description notes return includes voxel counts and centroids, and covers limiting behavior. It lacks details on ordering or error handling, but is sufficient for a simple listing tool.

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 0%, but the description adds full semantic meaning: query is a substring/fuzzy filter, limit is capped at 200 with default 50. This goes well beyond the bare schema types.

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 tool lists or searches atlas regions with voxel counts and centroids, using specific verb and resource. It distinguishes from siblings like load_atlas (loading) and roi_stats (statistics).

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 explains when to use the query parameter (substring/fuzzy filter) and that omitting it returns everything. It also notes the limit cap at 200. However, it lacks explicit contrast with sibling tools like roi_stats or compare_volumes.

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