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 safe, pure-computation profile is fully covered structurally. The description adds nothing beyond that — no note about rounding/precision, accepted unit spellings, or error behavior — which is acceptable but unambitious given annotations carry the safety story.

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?

One short sentence, no filler, unit list front-loaded. It is appropriately terse for a simple converter, though the terseness leaves the gaps noted elsewhere.

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?

With an output schema present and all three params described in the schema, the basic contract is complete. Missing are unit-string casing/aliasing rules (e.g., 'psi' vs 'PSI') and disambiguation from calculator_physics_pressure, both realistic sources of wrong invocation.

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%, but the schema itself carries a vacuous description for 'value' ('Value.') and no enums, so the description's unit list is the only signal of valid from_unit/to_unit strings. That makes it genuinely additive rather than redundant.

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+resource ('Convert pressure') and enumerates the supported units (Pa, bar, atm, PSI, mmHg), which tells an agent exactly what domain this covers. It does not, however, differentiate itself from close siblings such as calculator_physics_pressure (pressure computation) or generic calculator_convert.

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 statement of when to use this tool versus calculator_convert, calculator_pressure's nearest alternatives, or calculator_physics_pressure. Usage is only implicit from 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.