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

No annotations are present, so the description carries the full burden. It mentions that the tool 'Returns: {input}', which hints at the output format but is vague. Being a simple conversion tool, the behavior is predictable, but the description could disclose more about precision, edge cases, or whether the conversion is exact.

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?

The description is three sentences, front-loaded with the core purpose. Every sentence adds value: purpose, use cases, and a pointer to related tools. No fluff or redundancy.

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 conversion tool with full parameter schema and an output schema (though not detailed), the description covers the essentials. It mentions the return format and points to list_bundles for related calculators. Additional details like value limits or real-time rates are not critical. Minor gap: the '{input}' return description could be clearer.

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 input schema covers all three parameters (value, from, to) with full descriptions and enums. The description repeats the parameter names and lists the supported units, adding little beyond what the schema provides. With 100% schema coverage, a baseline of 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?

The description clearly states the verb 'Convert' and the resource 'area' with a specific list of units. It distinguishes from sibling tools like convert_distance or convert_volume by naming area-specific units (m², km², ha, etc.). The purpose is immediately apparent.

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 provides context by suggesting use cases ('real estate, agriculture, or construction') and references a related tool ('See list_bundles for related conversions calculators'). However, it does not explicitly state when not to use this tool or name direct alternatives, but the context is clear enough.

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