List available Flux resources and capabilities. Start here: every other tool takes a resource_id from this list, and a resource's capabilities say which of them it will accept.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| api | Yes | Prefix of the Flux API these resources are reached through. | |
| resources | Yes | ||
| usage_rules | No |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "api": {
+ "description": "Prefix of the Flux API these resources are reached through.",
+ "type": "string"
+ },
+ "resources": {
+ "items": {
+ "properties": {
+ "capabilities": {
+ "description": "Which reads this resource accepts: get_many, get_one, search.",
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ },
+ "description": {
+ "description": "The only free text about what a collection holds. Empty when the owner set none.",
+ "type": "string"
+ },
+ "name": {
+ "type": "string"
+ },
+ "path_template": {
+ "type": "string"
+ },
+ "required_parents": {
+ "description": "Placeholders the `parents` argument must fill for a nested resource.",
+ "items": {
+ "properties": {
+ "name": {
+ "type": "string"
+ },
+ "required": {
+ "type": "boolean"
+ },
+ "resource": {
+ "type": "string"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "resource_id": {
+ "description": "Pass verbatim as `resource_id` to every other tool.",
+ "type": "string"
+ },
+ "schema_ref": {
+ "type": "string"
+ },
+ "title": {
+ "type": "string"
+ },
+ "writable": {
+ "description": "Empty unless the key carries write grants for this resource.",
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "resource_id",
+ "capabilities"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "usage_rules": {
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "api",
+ "resources"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds the behavioral context that this is the canonical source for resource_ids and capabilities, which is useful. However, it doesn't describe the output structure or whether the list is exhaustive, though the output schema likely covers that.
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 sentences with zero waste. The first sentence states the action and resource; the second sentence front-loads the critical usage guidance. Every word earns its place.
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 zero-parameter discovery tool with a rich output schema and annotations covering safety, the description is nearly complete. It explains the tool's role in the overall workflow. The only minor gap is not explicitly stating that the output is a list of resource objects, but the output schema covers that.
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 tool has zero parameters, so the schema is trivially complete. The description adds meaning by explaining that the output (resource_ids and capabilities) is the input to every other tool, which is valuable context beyond the empty schema. Baseline 4 for zero params 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 a specific verb ('List') and resource ('available Flux resources and capabilities'), and explicitly positions itself as the entry point for all other tools. This clearly distinguishes it from siblings like describe_resource and query_records, which operate on specific resources or records.
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 explicitly says 'Start here' and explains that every other tool takes a resource_id from this list, and that a resource's capabilities say which tools it will accept. This gives the agent a clear when-to-use directive and implicitly tells it not to use this tool for anything else.
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.