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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds only the 'today' time window and the returned measurements; it says nothing about freshness, timezone, volume of results, or whether the feed is empty outside certain regions.

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 short sentence with the resource front-loaded and no filler. It is efficient, though it is terse to the point of leaving ambiguity that a few more words could have resolved.

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 parameters and no output schema, the description carries the full burden of explaining what comes back, and it only gestures at this via 'height, speed and climb'. It omits what a radiosonde record looks like, whether the list is bounded, and how it differs from the _at variant, leaving meaningful gaps for a data-feed tool.

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 takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies; the description does not need to compensate for any parameter gap.

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 identifies the resource (radiosondes) and a scope (heard today) plus three returned fields (height, speed, climb), but it uses no verb and the phrase 'heard' is cryptic about whether this is live reception, a stored log, or an observation feed. It also fails to distinguish itself from the sibling cell_sensor_sondes_at, which an agent would naturally compare it against.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites, and no mention of the obvious sibling cell_sensor_sondes_at (which presumably narrows to a time or location). The agent must infer the choice from name patterns alone.

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