Retrieve media items from a Plex library section grouped by folder, using the section ID to identify the library.
Get By Folder.
GET /library/sections/{sectionId}/byFolder
Args: section_id: The unique identifier of the library section
| Name | Required | Description | Default |
|---|---|---|---|
| section_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. However, the description adds no behavioral context about what 'by folder' retrieves, whether results are nested, or any special response semantics; it merely repeats the HTTP path.
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 short and parseable, but its headline 'Get By Folder.' is redundant with the tool name and does not earn its place. The endpoint and Args lines are useful, yet the overall terseness crosses from concise into under-specified.
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?
Although the tool has only one required parameter and an output schema, the description leaves the core 'by folder' semantics unexplained. An agent cannot confidently choose this tool over its many section-based siblings without knowing what folder-scoped retrieval means or when it applies.
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?
With 0% schema description coverage, the description needed to compensate, but it only says section_id is 'the unique identifier of the library section,' which adds little beyond the schema title 'Section Id.' It does not explain how the parameter interacts with the byFolder behavior.
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 is essentially a tautology: 'Get By Folder.' restates the tool name without explaining what 'by folder' means or what data is returned. The endpoint path adds structure but does not clarify the operation's purpose or distinguish it from the many similar get_library_sections_by_section_id_* siblings.
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?
No guidance is given about when to use this tool versus alternatives such as get_library_sections_by_section_id_all, by_resolution, or by_year. The description only states the endpoint and argument, leaving the selection criteria entirely implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.