Create a custom filter in Sonarr to control media library views, enabling tailored content organization and search.
Create CustomFilter.
POST /api/v3/customfilter
Args: body: Request payload. Read the matching GET or the /schema endpoint first to see the fields this resource expects.
| Name | Required | Description | Default |
|---|---|---|---|
| body | 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 indicate readOnlyHint=false, destructiveHint=false, idempotentHint=true. The description does not contradict these but also does not elaborate on any behavioral nuances beyond the endpoint. It mentions the need to read schema, which is helpful. However, it does not discuss potential side effects or response behavior, but the presence of annotations covers the safety profile, so a 3 is fair.
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 very short, almost terse, but it front-loads the key action and endpoint. The advice to read the GET/schema endpoint is placed after the args, which is a minor structural issue. It is efficient but could integrate the guidance more prominently.
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?
The tool has a body parameter that is an open object, and the description is the only source for field documentation since schema coverage is 0%. It does point to the GET/schema endpoint, which is a useful workaround, but this is not self-contained. With many sibling tools, the description should provide more specific guidance to avoid misuse. It's minimally adequate.
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%, and the description provides no additional meaning for the 'body' parameter. It merely says 'body: Request payload.' The description does not compensate for the lack of schema documentation. This is a significant gap because the body is an open object with additionalProperties, and the agent has no idea what fields to include without external reference.
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 indicates a POST operation to create a custom filter, with the endpoint path. However, it doesn't differentiate from the dozens of other create_ sibling tools beyond the resource name, which is in the tool name itself. It conveys the action and resource, but not the uniqueness constraints.
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 advises reading the matching GET or /schema endpoint to understand expected fields, which guides the agent on prerequisites. It does not explicitly state when to use this tool instead of alternatives, but the resource-specific nature makes it clear enough. This is slightly above average.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.