Watch SimVar Over Time

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

Beyond the readOnlyHint and destructiveHint annotations, the description discloses a valuable failure behavior: it fails fast on the first read error instead of wasting the full sampling duration. This directly informs agent expectations about error handling and performance.

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 only two short paragraphs, with the core behavior front-loaded in the first sentence and the key failure mode in the second. Every sentence contributes meaningful information with 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?

With a complete 100% parameter schema, an output schema, and annotations covering read-only and non-destructive behavior, the description adds what structured data cannot: the time-series purpose and fail-fast behavior. Nothing essential for correct invocation is missing.

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 the baseline is 3. The description does not add parameter-level meaning beyond the schema, though the mention of 'name or unit' in the fail-fast note lightly reinforces those parameters' roles.

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 uses 'Sample a SimVar over time' with a specific verb and resource, and 'returning a time series' makes the output explicit. This clearly distinguishes it from one-shot alternatives like msfs_get_simvar and msfs_get_simvars_bulk.

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?

'For debugging' gives a clear context and 'over time' implies the use case, but the description never names alternative tools or states when not to use this one. The guidance is present only by implication, not explicit routing.

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