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

Annotations provide only a title with no readOnlyHint or destructiveHint, so the description carries the full burden. It notes a pollen caveat ('where it is counted') and lists measured parameters, but it does not disclose data source, update frequency, or any safety concerns. The read-only nature is implied but not explicitly stated.

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, dense sentence with no filler. It front-loads the primary purpose ('Air quality at a location right now') and efficiently lists the included measurements and the pollen caveat.

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 two-parameter tool with no output schema, the description adequately summarizes what is returned (AQI, PM2.5, PM10, etc.). It covers the temporal scope and the pollen availability caveat. Missing units or response structure, but the description is sufficient for an agent to select and invoke the 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?

Schema coverage is 100%, with both lat and lon described. The description adds 'at a location' but no further detail on coordinate ranges or formats. It does not explain how parameters map to the listed metrics, so value beyond the schema is minimal.

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 identifies the tool as providing current air quality data, listing specific metrics (AQI, PM2.5, PM10, etc.). It distinguishes from weather_forecast and weather_history through 'right now' and 'air quality' focus, though it lacks an explicit verb like 'get' or 'retrieve'.

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 implies usage for current air quality queries but does not explicitly state when to prefer it over weather_forecast or weather_marine. No exclusions or alternative tool names are provided, so guidance is implied rather than explicit.

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