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

With no annotations supplied, the description carries the burden and does disclose that the tool is "pure CPU, instant" — signalling no network calls, no auth, no side effects, and negligible latency. It stops short of stating determinism, precision/rounding behavior, or whether the unit list is exhaustive (e.g. mmHg, torr), which matters for a conversion tool.

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?

Two short sentences, front-loaded with the purpose and units, followed by a one-clause performance note. Nothing is padded and nothing important is buried.

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 three-parameter converter with no output schema, an agent still lacks the return shape (bare number? labeled string?), the unit-string format (case sensitivity, abbreviations like "kpa"), and whether unsupported units error or pass through. The description is serviceable but not fully self-sufficient.

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 nominally 100%, but the schema descriptions are placeholders ("Target unit", "Source unit", "Value") and there are no enums. The description is the only place the accepted unit tokens (bar, psi, kPa, atm) are listed, which directly defines valid values for from/to — genuine added meaning 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 pressure units") and enumerates the supported units (bar, psi, kPa, atm), so the domain is unambiguous. It does not, however, distinguish itself from siblings like unit_convert or convert_units that likely also perform conversions, leaving the agent to guess which to pick.

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?

No when-to-use or when-not-to-use guidance is given. Given the presence of generic siblings (unit_convert, convert_units), the description should say something like "use for pressure; use unit_convert for mixed-unit or unsupported units" — it says nothing about alternatives or selection criteria.

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