units.pressure_convert

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

Annotations already declare readOnly/idempotent/closed-world, and the description adds non-obvious traits beyond them: units are case-sensitive, magnitude must be a Decimal string, and gauge/absolute pressure semantics are ignored. That is meaningful context the annotations cannot convey.

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?

Four short sentences, purpose front-loaded, then the unit vocabulary, then the precision caveat, then the return shape. Every sentence supplies information the schema or annotations do not.

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, the return-value sentence is slightly redundant, but the description fully equips an agent to call a simple 3-param converter: valid units, case rules, numeric type, and the semantic limitation. Nothing critical is missing.

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 0%, so the description carries the burden, and it does: it documents all three parameters by specifying the magnitude type (Decimal string) and the full valid unit vocabulary for from_unit/to_unit plus case sensitivity. Minor gaps remain (no explicit alias or default handling).

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 (pressure units) and enumerates the exact supported unit set, which effectively scopes it away from generic siblings like units.convert or units.energy_convert without needing to name them.

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?

Usage context is clear from the unit list, and it adds a genuine boundary condition: this is a pure scale conversion that does not account for gauge vs absolute pressure, which tells the agent when the tool is inappropriate. No explicit alternative tool is named, 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.