hourly_dataHourly data for (station, sensor). CDEC's -9999 missing marker is returned as value: null with missing: true, and the response counts the gaps.
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | ||
| start | Yes | ||
| sensor | Yes | ||
| station_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| body | No | Raw text response from API | |
| format | No | Indicates response is plain text (non-JSON) |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "sensor": 1,
+ "start": "2024-01-01T00:00:00",
+ "station_id": "SHA"
+ },
+ {
+ "end": "2024-01-02T12:00:00",
+ "sensor": 2,
+ "start": "2024-01-01T12:00:00",
+ "station_id": "ORO"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "additionalProperties": true,
+ "description": "Response from CDEC API containing hourly time series data or raw text",
+ "properties": {
+ "body": {
+ "description": "Raw text response from API",
+ "type": "string"
+ },
+ "format": {
+ "description": "Indicates response is plain text (non-JSON)",
+ "enum": [
+ "text"
+ ],
+ "type": "string"
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark the tool as read-only and non-destructive, so the description adds value by disclosing how CDEC's -9999 missing marker is normalized to null with missing:true and that gap counts are included. This is meaningful behavioral context beyond the 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 a single sentence with the core purpose front-loaded and the missing-marker behavior stated succinctly afterward. There is no filler or repetition.
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 four-parameter data retrieval tool with no parameter descriptions in the schema, the description is too spare. It omits required start semantics, time range behavior, units, and any guidance for choosing this over daily_data, so invocation context remains incomplete despite an output schema being present.
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 description coverage is 0%, and the description only names station and sensor. It does not explain the start parameter, the optional end parameter, expected formats, or sensor/station conventions, leaving the agent without enough information to construct a valid request.
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 names the resource as hourly data for a station-sensor pair, which distinguishes it from sibling tools like daily_data and event_data. It lacks an explicit verb like 'retrieve' or 'fetch', but the title and phrasing make the operation evident.
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 provides no explicit guidance on when to use this tool versus alternatives such as daily_data or event_data. The only usage hint is the word 'hourly', which is implied rather than stated as a selection criterion.
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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