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

Annotations already declare read-only, idempotent, non-destructive, closed-world, so safety is well covered. The description adds genuine behavioral value beyond that: the algorithm (Magnus formula) and the shape of the result (dew point °C plus a comfort class).

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?

Three short, front-loaded sentences with no waste; the purpose leads and the sibling pointer trails. Minor overlap with schema-documented inputs keeps it out of 5 territory.

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 two-parameter pure calculator with full schema coverage, an output schema, and complete safety annotations, this is essentially complete. The only missing element is guidance on edge cases (e.g., humidity bounds), which is minor.

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% and the two parameters are fully documented there with units. The description simply restates them (temperature °C, humidity %), adding no range, format, or edge-case meaning beyond the schema. Baseline 3 is appropriate.

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 (compute), resource (dew point temperature), and even the method (Magnus formula). Distinguishes it from nearby siblings like calculate_heat_index and calculate_wind_chill, which are similarly weather-comfort calculators.

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?

Gives clear context for use (HVAC, weather, comfort analysis) but names no alternative and no when-not-to-use condition. It points to list_bundles for related calculators, which is a sibling reference rather than an alternative for this specific computation.

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