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

Annotations cover the safety profile (read-only, idempotent, non-destructive), but the description adds distinct behavioral facts the annotations cannot convey: the tool opens an interactive card the user must act on, the file is read on-device with nothing uploaded, and the totals must be shared back into the conversation by the user. These are essential operational characteristics.

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?

Four sentences, each carrying information: source formats, privacy behavior, resulting output, and usage trigger. It is front-loaded with the mechanism, though the output-content sentence partially overlaps the output schema and could be trimmed.

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?

An output schema exists, so return values need not be restated. Given the zero-parameter, annotation-rich, interactive nature of the tool, the description covers everything an agent needs to know before invoking it.

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, so the baseline is 4. The description correctly implies no input is needed and compensates by explaining the user-driven flow that replaces formal parameters.

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 and resource (import a logbook export) and immediately scopes it to the concrete sources (ForeFlight, Garmin Pilot, LogTen). This cleanly separates it from estimate_flight_hours, which computes rather than imports an actual logbook.

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 final sentence gives an explicit trigger: 'Use it when someone wants the CO₂ of their flying from their logbook.' That is a clear usage context, though it stops short of naming alternatives or stating when NOT to use it (e.g., when the user has no logbook export).

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