nylas_list_foldersList mail folders/labels for the connected account. Nylas v3: GET /v3/grants/{grant_id}/folders.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max folders to return. | |
| grant_id | No | Connected-account grant id. Overrides NYLAS_GRANT_ID for this call. |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the tool is known to be non-destructive. The description adds no further behavioral traits (e.g., pagination, rate limits, scope of folders). It only restates the endpoint, which is not a behavioral detail.
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 one sentence plus an endpoint reference, which is concise and front-loaded. However, the endpoint line adds little for agent decision-making and could be considered extraneous.
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 list tool with two optional parameters and no output schema, the description is minimally adequate. It omits details about the returned folder objects (e.g., fields), which an agent might infer but is not explicitly provided.
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 100% (both parameters have descriptions in the schema). The tool description does not add additional meaning beyond the schema; it merely rephrases the context. 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 states the tool lists mail folders/labels for the connected account, with a specific verb and resource. It distinguishes from sibling list tools (e.g., list_messages) by the resource type, though it does not explicitly contrast them.
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 no guidance on when to use this tool versus alternatives like list_messages or list_drafts, nor mentions any prerequisites or context for opting for this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct resource and action: create vs list vs get for specific entities like draft, event, calendar, contact, grant, message, folder. There is no overlap, as even similar verbs like 'list' are paired with unique nouns. Agents can easily select the correct tool.
All tool names follow a uniform 'nylas_verb_noun' pattern using snake_case, with clear and predictable verbs (create, get, list, send) and nouns (draft, event, calendar, etc.). The naming is fully consistent across all 15 tools.
With 15 tools, the set is well-scoped for a Nylas integration covering email, calendar, and contacts. Each tool serves a clear purpose without redundancy, and the count falls comfortably within the ideal range of 3-15 tools.
The tool set covers reading and limited creation (drafts, events) but lacks update and delete operations for all entities, as well as create for contacts. This leaves notable gaps for full lifecycle management, though core workflows like listing and fetching are present.