Fetch the latest temperature, humidity, battery level, check-in time, and offline status for a sensor ID. Use it to monitor freezer, fridge, or other monitored environments.
Get the latest reading for one sensor: temperature (Celsius and Fahrenheit), humidity, last check-in, battery level and offline status.
| Name | Required | Description | Default |
|---|---|---|---|
| sensor_id | Yes | Sensor ID, as returned by list_sensors. |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose the return payload (temperature in C and F, humidity, last check-in, battery, offline flag) plus the read-only nature implied by "Get." It says nothing about behavior for unknown sensor IDs, stale data, or unit/format details beyond the field list.
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 sentence that front-loads the verb and resource before the field enumeration. Every clause earns its place and there is no filler.
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 one-parameter read tool with a fully documented schema, the description is nearly sufficient, and the field list compensates for the absent output schema. Minor gaps remain around error behavior for invalid IDs and how fresh "latest" data is.
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 100% and the sensor_id description already points at list_sensors as the source of valid IDs. The description adds no additional parameter meaning, so the baseline 3 applies.
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 gives a specific verb and resource ("Get the latest reading for one sensor") and enumerates the returned fields, so the agent knows exactly what comes back. It does not explicitly name get_readings_history as the alternative for historical data, so the split with that sibling must be inferred from the word "latest."
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?
"Latest reading" implies a current-state lookup rather than a historical query, which gently signals when to use it over get_readings_history, but the description never states the condition explicitly nor excludes any case. The single-use context is left to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.