Hopi

Add working days

hopi_add_working_days

Read-onlyIdempotent

Add or subtract a number of working days (Monday to Friday) from a start date, optionally skipping England and Wales bank holidays. Dates use the YYYY-MM-DD format. Bank holiday data covers 2026 and 2027 only, so outside those years just weekends are skipped. Source: https://hopi.co.uk/add-working-days/

Input Schema

TableJSON Schema

Name	Required	Description	Default
`days`	Yes	Number of working days to move (0 to 100000)
`start`	Yes	Start date in YYYY-MM-DD format
`direction`	No	'add' to count forwards, 'sub' to count backwards (default 'add')	add
`bankHolidays`	No	Also skip England and Wales bank holidays, not just weekends (default true)

Output Schema

TableJSON Schema

Name	Required	Description
`days`	No
`start`	No
`result`	No
`summary`	Yes
`weekday`	No
`complete`	No
`warnings`	No
`direction`	No
`resultLong`	No
`source_url`	Yes	The tool's page on hopi.co.uk (cite or open to check the figure)
`daysSpanned`	No
`bankHolidays`	No
`holidayCoverage`	No
`holidaysSkipped`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedSep 20, 2026
- addedOutput schema / properties / complete
```
Added value: +{
+  "type": "boolean"
+}
```
- addedOutput schema / properties / holidayCoverage
```
Added value: +{
+  "type": "object"
+}
```
- addedOutput schema / properties / warnings
```
Added value: +{
+  "type": "array"
+}
```
- addedOutput schema / required
```
Added value: +[
+  "source_url",
+  "summary"
+]
```
First observedSep 20, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered; the description adds genuinely useful behavioral context by explaining that bank holiday data is only for 2026 and 2027 and that outside those years only weekends are skipped. It does not contradict the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The main behavior is front-loaded and the description is compact; the source URL is marginally unnecessary for selection/invocation but does not add meaningful clutter. Overall, every substantive sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description, together with rich schema descriptions and output schema, covers most selection and invocation needs, including the important 2026/2027 bank-holiday limitation. It is slightly incomplete on edge-case behavior, such as how a weekend or holiday start date is treated when adding/subtracting.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 100% schema coverage, the baseline is 3, but the description adds value by fixing date format ('YYYY-MM-DD') and, more importantly, the bank-holiday data limitation that directly affects the bankHolidays parameter. The add/subtract wording maps cleanly to the days and direction parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific operation—'Add or subtract a number of working days (Monday to Friday) from a start date'—with a clear resource and optional bank-holiday behavior. This also differentiates it from sibling hopi_working_days_calculator, which implies counting days between dates rather than shifting a date.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The use case is implied by the verb phrase and the 'optionally skipping... bank holidays' option, but there is no explicit mention of when not to use it or a named alternative such as hopi_working_days_calculator for counting working days between two dates. Clear context, but no explicit routing/exclusions.

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

All Hopi tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?