list_sourcesReturn all official data sources (id, title, homepage URL) that EONET aggregates natural-event records from.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| sources | Yes | List of official EONET sources |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {}
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "sources": {
+ "description": "List of official EONET sources",
+ "items": {
+ "properties": {
+ "id": {
+ "description": "Source id",
+ "type": "string"
+ },
+ "link": {
+ "description": "Source link",
+ "type": "string"
+ },
+ "source": {
+ "description": "Source name",
+ "type": "string"
+ },
+ "title": {
+ "description": "Source title",
+ "type": "string"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "sources"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds useful context: it returns specific fields (id, title, homepage URL) and clarifies that sources are 'official' from EONET. No contradictions 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?
The description is concise—one sentence that conveys the purpose, resource, and output structure. It is front-loaded with the verb and resource, making it easy to parse quickly.
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?
Given the tool has zero parameters, an output schema exists, and the description explains what is returned and why, the description is fully complete for its simplicity. No additional information is needed.
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 schema coverage is 100%. The description adds no parameter-specific information, which is acceptable as there are no parameters to describe.
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 states the verb 'Return', the resource 'all official data sources', and specifies the fields returned (id, title, homepage URL) along with the context of EONET aggregating natural-event records. It distinctly sets the tool apart from its siblings, as no other tool appears to list sources.
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 implies usage for fetching a list of sources, but does not explicitly state when to use this tool over alternatives or provide any exclusion criteria. However, given the tool's simplicity and lack of similar siblings, the intended use is clear enough.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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