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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds only the unit vocabulary and a vague 'Returns: {input}' note, which is largely redundant with the output schema, so it contributes little beyond structured data.

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 compact sentences with the scope front-loaded and no filler. The trailing 'Returns: {input}. See list_bundles...' sentence is slightly noisy given an output schema exists, but overall it is tight.

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 closed-world pure conversion with full annotation coverage, 100% schema coverage, and an output schema, the description covers purpose, units, and usage context adequately. It is only marginally incomplete in not clarifying the enum label mapping or return shape, both of which are already structured.

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 enums on both 'from' and 'to', so the schema already documents the parameters. The description's unit list (km/h, mph, m/s, knots, ft/s) loosely maps those labels to the enum values (kmh, mph, ms, knots, fts), but does not explain the value/source/target roles. 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 (Convert) and resource (speed) and enumerates the exact unit set (km/h, mph, m/s, knots, ft/s). This cleanly distinguishes it from neighbors such as convert_distance, convert_pressure, and calculate_speed_distance_time.

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 concrete application contexts (travel, sport, maritime/aviation) and routes the agent to list_bundles for related conversion calculators. It does not state exclusions or contrast with the sibling calculate_speed_distance_time, so it stops short of a 5.

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