brain-mcp

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=false. The description adds useful context about what metadata is returned (path, title, type, updated date, status) and filterable frontmatter types, which goes beyond annotations. However, it doesn't mention behavioral aspects like pagination, rate limits, or authentication needs.

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 well-structured with purpose, usage examples, parameters summary, and return information. It's appropriately sized, though the Args/Returns sections could be more integrated with the main text. Every sentence adds value, with no 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?

Given the tool has annotations covering safety (readOnly, non-destructive) and an output schema exists, the description provides good context about what the tool does, when to use it, and what it returns. It adequately compensates for the 0% schema description coverage. The main gap is lack of explicit sibling differentiation.

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 schema description coverage is 0%, so the description carries full burden. It provides a high-level summary of parameters ('folder, note_type filter, recursive flag, limit') and clarifies the note_type filter values (moc, project, area, resource, archive). However, it doesn't explain parameter interactions or provide examples for the folder parameter.

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 ('List notes in a vault folder') and resource ('notes'), with explicit mention of optional filtering by type. It distinguishes from siblings like brain_search_notes (which likely searches content) and brain_list_folders (which lists folders, not notes).

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 provides clear context for when to use this tool ('Useful for browsing a folder, reviewing inbox contents, or finding all notes of a specific type'). However, it doesn't explicitly state when NOT to use it or name specific alternatives among siblings (e.g., brain_search_notes for content-based searches).

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