Current readings

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint, but the description supplies genuinely useful behavioral context: the cloud only receives data once per report interval (often 15 min), so readings can be late, and staleWarning signals lateness. That freshness semantics is exactly the kind of non-obvious trait an agent needs. It stops short of covering failure modes such as unknown device names or multi-device ambiguity.

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?

Front-loaded with the resource and the metric list, then the freshness semantics; every sentence carries information. The parenthetical metric enumeration with an ellipsis and the 'good / high — ventilate…' shorthand make it slightly loose, but nothing is padding.

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?

With no output schema, the description correctly takes on the burden of explaining return fields (readingAt, ageMin, staleWarning) and the level interpretation, which is what an agent needs to reason about the payload. Only the device-resolution behavior is left unaddressed.

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% for the single optional 'device' parameter, so the schema already explains that a name or MAC is accepted and optional for single-device accounts. The description never mentions device selection at all, adding nothing beyond the schema — 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?

States a specific verb+resource ('Latest readings of Qingping sensors') and enumerates the covered metrics (CO₂, PM2.5, PM10, tVOC, temperature, humidity, battery). The word 'Latest' implicitly separates it from qingping_history, but no sibling is named, so differentiation is left to inference.

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 only implied: 'Latest' suggests polling current state rather than retrieving a time series (qingping_history) or configuring reporting (qingping_set_intervals). There is no explicit when-to-use or when-not-to-use statement and no routing to alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.