Calculate the difference between two ISO dates in the requested unit (ms / seconds / minutes / hours / days / weeks).
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | Later ISO date/datetime. | |
| from | Yes | Earlier ISO date/datetime. | |
| unit | No | days |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must cover behavior. It describes the core operation but lacks details on error handling, timezone assumptions, sign of result, or validation of ISO format. Adequate but not rich.
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?
Single sentence with no redundancy: efficiently states purpose and parameters. Perfectly front-loaded.
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?
No output schema and description omits return value format or behavior on invalid input. For a simple calculator this is acceptable but leaves some ambiguity, given no annotations.
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 67%; description adds mention of units (ms, seconds, etc.) but does not significantly enhance understanding beyond the schema's parameter descriptions and enum values.
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 'Calculate the difference between two ISO dates in the requested unit' with a specific verb and resource, distinguishing it from sibling tools like convert_currency or list_timezones.
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 implies usage for date difference calculations but does not provide explicit guidance on when to use versus alternatives, nor does it note prerequisites or ordering constraints beyond what the schema indicates.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool has a distinct purpose: currency conversion, timezone conversion, unit conversion, date difference calculation, and listing supported entities. There is no overlap, so an agent can easily choose the correct tool.
Tools follow a consistent verb_noun pattern (e.g., convert_currency, list_timezones). The only minor deviation is 'date_diff' which uses noun_noun, but it is still clear and fits the pattern of other tools.
With 6 tools, the set is well-scoped for a unit and currency converter. It covers all necessary operations without being too sparse or overwhelming.
The tools provide full conversion capabilities (currency, timezone, unit), date difference calculation, and listing helpers for timezones and units. There are no obvious gaps for the server's stated purpose.