MCP-ADAPTER

time_list_timezones

List IANA timezone names, with optional substring filtering, to find valid timezone identifiers for scheduling, logging, or time conversion.

Instructions

List IANA timezone names, optionally filtered by substring (e.g. 'Asia', 'London').

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "time_list_timezones"
  }
}

Input Schema

Name	Required	Description	Default
`limit`	No
`filter`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 27, 2026

TDQS

A3.5/5.0

Behavior3/5

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

No annotations are provided, so the description must carry the behavioral burden. The verb "List" clearly conveys a safe read-only enumeration, but there is no mention of pagination (the limit param implies batching), result size, or browsing behavior, leaving meaningful gaps.

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

Conciseness5/5

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

A single tight sentence with the core purpose front-loaded and the filter behavior and examples appended. No wasted words.

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

Completeness3/5

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

For a low-complexity list tool with an output schema (so return values need not be described), the definition is mostly adequate, but the undocumented limit parameter is a real hole and no alternative routing is offered among numerous time siblings.

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

Parameters3/5

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

Schema description coverage is 0%, so the description must compensate. It successfully explains the filter parameter's semantics (substring matching) with examples, but completely omits the limit parameter, leaving half the parameters undocumented anywhere.

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

Purpose4/5

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

States a specific verb and resource ("List IANA timezone names") plus the optional filter capability, so an agent can quickly tell it retrieves timezone identifiers. It does not explicitly differentiate itself from time siblings like time_world_clock or time_convert, leaving that inference to the agent.

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 description implies the usage context via "optionally filtered by substring" with concrete examples ('Asia', 'London'), which hints at lookup/discovery scenarios. However, it never states when to use this versus sibling timezone-related tools, nor any conditions or exclusions.

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