Returns the current UTC time, optionally formatted, so agents and clients can timestamp events and coordinate schedules using a single reference clock.
Current UTC time.
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": "now_utc"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| format | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden, and it discloses almost nothing: no return format, no precision, no mention of whether the optional format argument changes behavior. 'UTC' at least disambiguates the timezone, which is the only behavioral fact conveyed.
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?
It is extremely short and front-loaded with zero filler, but the brevity comes at the cost of under-specification rather than tight editing. Nothing is wasted, yet very little is said.
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 trivial read-only time tool an agent might get by, but the description leaves both the return shape (timestamp string? object?) and the 'format' parameter completely unexplained, with no output schema to fall back on.
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?
The single optional parameter 'format' has 0% schema description coverage and the description says nothing about it — no accepted values, no default, no effect on output. With low coverage the description was expected to compensate, and it does not.
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 fragment 'Current UTC time.' identifies the resource unambiguously and is obviously distinct from siblings like add/sqrt/echo, but it lacks a verb and any explicit scope statement. An agent can infer the purpose, but the definition does the bare minimum.
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?
There is no guidance on when to call this versus alternatives, nor any mention of prerequisites or typical use cases. The description simply asserts existence of the tool without any routing help.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.