Retrieve saved AllTrails lists (favorites, custom) for a user. Defaults to the signed-in user; supply a userId to view a public profile.
List an AllTrails user's saved lists (favorites, custom lists). Defaults to the signed-in user; pass a userId to target a specific public profile.
| Name | Required | Description | Default |
|---|---|---|---|
| userId | No | Numeric AllTrails user id. Defaults to the signed-in user. |
Changes observed during successful MCP inspections.
v3.0.0Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already indicates a safe read operation. The description adds useful context about favorites/custom lists and that userId targets a public profile, but does not describe return shape or pagination. No contradiction with annotations.
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 concise sentences front-load the action and object, then provide the only necessary scope detail. There is no filler or 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?
For a simple read-only operation with one optional parameterachment, the description covers purpose, scope, and target-user selection. Return value details are not providedhol, but they are reasonably inferable for a list operation and no output schema exists to clarify further.
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%, and the userId parameter description already states that it defaults to the signed-in user. The tool description reinforces this and adds the 'specific public profile' detail, but does not add substantial meaning beyond the schema.
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?
States the specific verb 'List' and the resource 'an AllTrails user's saved lists', with a parenthetical clarifying that it includes favorites and custom lists. This is distinct from siblings like alltrails_get_list_items, which operates on the contents of a single list.
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 clearly explains the default behavior for the signed-in user and how to target a specific public profile by passing userId. It does not explicitly name alternatives or state when not to use this tool, but the context is sufficient for basic selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.