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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered without the description's help. The one piece of real added value is the enumeration of accepted unit tokens, which the description supplies where the schema has no enums. No mention of case sensitivity, unit aliases, precision, or rounding behavior.

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?

A single short sentence, front-loaded with the verb and immediately followed by the unit vocabulary. Nothing redundant, nothing padded.

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 explained, and all three required params are covered at the schema level. Still missing for a converter in a crowded namespace: valid unit string formatting, precision of results, and a pointer away from the generic calculator_convert sibling.

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 a baseline of 3 would apply, but the schema's own parameter descriptions are near-vacuous ('Value.') and contain no enums for from_unit/to_unit. The description fills exactly that gap by naming the valid unit strings an agent must pass, which is meaningful value beyond the schema.

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 ('Convert speed') and enumerates the four supported units, so the operation is unambiguous. It does not, however, distinguish itself from siblings like calculator_convert or calculator_physics_speed, which an agent could plausibly reach for instead.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no alternative is named despite a large sibling set containing a generic unit converter (calculator_convert) and a physics speed calculator. Usage is only implied by the tool name and unit list.

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