Frontier Signal MCP

List observed dates

list_observed_dates

Read-onlyIdempotent

Lists baseline and public brief dates available in the current checkout by reading recorded filenames and observed fields; no live fetch is performed.

Instructions

List baseline dates (and public brief dates) available in this checkout.

Dates come from filenames and the observed field. No live fetch is performed.

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": "list_observed_dates"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Output Schema

Name	Required	Description	Default
`dates`	Yes
`latest`	Yes
`brief_dates`	Yes
`latest_brief`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Nov 6, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false. The description adds meaningful context beyond that: dates derive from filenames and the observed field, and 'No live fetch is performed,' which clarifies the data's provenance and staleness characteristics.

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?

Two short sentences with the core purpose front-loaded and the provenance note immediately after. There is no redundant or filler wording.

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

Completeness5/5

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

The tool has no parameters, rich annotations covering safety and openness, and an output schema that carries return-value structure. The description supplies the remaining useful context about where dates come from and that no network call occurs.

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?

The tool takes zero parameters, so there is no parameter semantics to explain; the schema correctly shows an empty object. A baseline of 4 is appropriate because the description cannot and need not add parameter-level meaning.

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?

The description uses a specific verb and resource — 'List baseline dates (and public brief dates)' — and adds scope with 'available in this checkout.' It is clear what the tool returns, though it does not explicitly distinguish itself from siblings like latest_brief or deltas.

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?

Usage is implied: an agent can infer this is for discovering which dates exist before fetching a brief or computing deltas. However, there is no explicit when-to-use/when-not guidance and no named alternatives, leaving routing to inference.

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

Deploy Server