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plot_identification

Plot pair-by-pair cross-correlation and partial correlation panels to identify time-series dependence, lead-lag direction, and candidate MA/AR orders before fitting joint VARMA models.

Instructions

FIGURE — Jenkins and Alavi's (1981) identification, pair by pair: the figure of identify_matrices. For each pair of series, in GraphMaker's CCF panel (Treadway's, the one drtran reads), the correlation function R_k above the partial S_k, both two-sided, same lag axis and scale — as art's ACF over PACF.

method=2 (default): the residuals of the univariate models (prewhitened, each series by ITS OWN model — Haugh's CCF, not a transfer function's). Band 2/sqrt(n); between the panels Haugh's S* (1976), the test that the two are independent, in total and by side (k > 0, k < 0: who leads). The CCF's cut-off after q suggests an MA(q) residual model. method=1: the stationary series w_t, not prewhitened. The CCF band is Bartlett's (3.13) for unrelated series, lag by lag: the series are not white, and a 2/sqrt(n) band would show their common cycles as cross terms. Here the partial is the decisive one: a cut-off after p suggests an AR(p). Each panel is titled "A - B", GraphMaker's order: A leads at k > 0. With three or more series the partial of a pair comes from the VAR of all of them — given the others — and pairs ("A-B, A-C") draws only those; read identify_matrices' determinants and + - . table first to choose them. nlags defaults to max(10, 2 x frequency); the partial stops at the order the sample supports (n / (3m)), marked on the panel.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

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

Input Schema

NameRequiredDescriptionDefault
nameYes
pathNo
nlagsNo
pairsNo
methodNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.2.0

TDQS

A3.5/5.0
Behavior4/5

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: prewhitening by each series' own model under method=2, Bartlett bands under method=1, panel titles, default lags, and the partial's stopping rule. It omits whether the plot is displayed or written to a file, but the computational behavior is unusually well specified.

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

Conciseness3/5

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

The purpose is front-loaded, and most sentences carry technical content, but the text is a dense run-on paragraph laced with jargon ('art's ACF over PACF', 'Haugh's S*'). It is appropriately sized for the complexity but would benefit from line breaks and less compressed phrasing.

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 complex statistical plotting tool with no annotations and no output schema, the description covers method behavior, defaults, pairs format, and prerequisites well. It still leaves name and path unexplained and does not state what the tool returns or where it writes the figure.

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 explains nlags (max(10, 2 x frequency)), pairs format ('A-B, A-C'), and method semantics, but never explains name or path, so two of five parameters remain opaque.

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?

Opening 'FIGURE — Jenkins and Alavi's (1981) identification, pair by pair: the figure of identify_matrices' states a specific visualization resource and ties it to a known analytical step. It is clear enough to distinguish from generic plotting siblings, but it never explicitly says 'plot' and does not contrast with plot_residual_ccf or identify_cross.

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 explains method=2 vs method=1 conditions and tells the user to read identify_matrices' determinants and +/- table first when choosing pairs. That implies when each method is appropriate, but there is no explicit 'use this tool when...' and no exclusion or alternative compared.

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