Fetch historical weather data for a given latitude, longitude, and Unix timestamp to examine past conditions at any location.
Get historical weather data for a specific timestamp (Time Machine).
| Name | Required | Description | Default |
|---|---|---|---|
| dt | Yes | Timestamp (Unix time, UTC) | |
| lat | Yes | Latitude | |
| lon | Yes | Longitude |
Changes observed during successful MCP inspections.
v1.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does not disclose read-only nature explicitly, data availability limits, historical range boundaries, or response shape — all relevant for a history endpoint.
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?
A single front-loaded sentence with no waste. The '(Time Machine)' parenthetical is unexplained jargon, a minor blemish on otherwise tight phrasing.
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 simple three-parameter read tool with a fully covered schema, this is minimally viable. With no annotations and no output schema, the missing historical-range and return-format context leaves a gap an agent would notice.
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 100%, so lat, lon, and dt are already documented in the schema. The description adds only the qualifier that the timestamp selects a historical point; the '(Time Machine)' tag adds no semantic value.
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?
States a specific verb (Get) and resource (historical weather data) plus the scoping constraint (a specific timestamp). It implicitly contrasts with the sibling get_current_weather via 'historical', but does not name or differentiate against it explicitly.
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?
Usage is implied: use this when you need weather for a past timestamp rather than the current conditions. There is no explicit when-to-use, when-not-to-use, or named alternative (get_current_weather) to route the agent.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.