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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds no behavioral details beyond these—no side effects, auth needs, or rate limits are applicable for a pure conversion. With the annotation bar lowered, the description performs adequately but adds no extra transparency credit.

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 sentences convey the full purpose and direction-specific behavior without fluff. The source URL is an extra clause but not intrusive. Information is front-loaded with the core action first, then the direction details. Very compact and effective, though the source link could be omitted without loss.

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 read-only converter with a full output schema and complete parameter descriptions, the description covers the essential usage: both conversion directions and which inputs are required. It does not mention rounding or precision, but the output schema likely handles that. Overall, it is sufficiently complete for an agent to call this tool correctly.

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 reiterates the direction-parameter mapping already present in the schema (e.g., 'cm' description says 'for cm-to-feet'), but adds no new semantic nuance like formatting, precision, or edge-case handling. It correctly reflects the conditional requirement but does not elevate above the schema baseline.

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 opens with a specific verb and resource: 'Convert a height between centimetres and feet/inches.' It explicitly names both directions and what each returns, which clearly distinguishes this from generic length converters like hopi_length_converter and other unit-specific siblings such as hopi_kg_to_stone or hopi_miles_to_km. The purpose is unambiguous and fully stated.

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 description explains which parameters to use for each direction ('Direction cm-to-feet takes cm... Direction feet-to-cm takes feet and inches...'), giving clear when-to-use context within the tool. It does not explicitly mention alternatives like 'use hopi_length_converter for other units,' but the specialized name and sibling set make that exclusion implicit. There is clear context, just no explicit exclusionary guidance.

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