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identify_matrices

Identifies AR and MA orders for multiple time series by computing prewhitened residual, partial, and Alavi q-conditioned correlation matrices, then comparing results with specification warnings.

Instructions

N2 — Jenkins and Alavi's (1981) two identifications, as matrices.

Method 2, prewhitened: the correlation matrices R_k of the residuals of the diagonal system (the univariate models' residuals), which suggest an MA residual model and its links. Method 1, not prewhitened: R_k, the partial correlation matrices S_k (multivariate Yule-Walker) and Alavi's q-conditioned S_k(q) of the stationary series of the same files, which suggest the AR (and ARMA) orders; determinants with three or more series. Then the comparison as a menu, with their warning when a cross AR shows: prewhitening can mis-specify it. nlags defaults to max(6, frequency); qmax the largest q-conditioning. Complements identify_cross (the pairwise CCFs).

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": "identify_matrices"
  }
}

Input Schema

NameRequiredDescriptionDefault
nameYes
qmaxNo
nlagsNo

Output Schema

NameRequiredDescriptionDefault
resultYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.2.0

TDQS

C2.8/5.0
Behavior3/5

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

With no annotations, the description carries the full burden. It discloses useful behavioral details: the prewhitening warning for cross AR, the determinants condition for three or more series, and defaults for nlags and qmax. However, it does not state whether the tool is read-only, requires data to be loaded first, or has any operational side effects, leaving a significant gap for a tool with zero annotation coverage.

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

Conciseness2/5

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

The description is a dense, run-on academic paragraph with heavy jargon and semicolons. It is not front-loaded with a clear action statement, and key information (purpose, methods, warning, defaults) is packed together rather than organized for quick agent parsing. Every clause may matter to an expert, but the structure is poorly suited to tool selection.

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?

Given the tool's complexity, the description is detailed about the mathematical methods and includes a warning and parameter defaults. However, it omits operational context such as data requirements, the meaning of the required `name` parameter, and when to use this tool versus its siblings. With no annotations and 0% schema coverage, these gaps matter, though the output schema reduces the need to explain return values.

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

Parameters2/5

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

Schema coverage is 0% and the description compensates for only two of three parameters: it explains that `nlags` defaults to max(6, frequency) and `qmax` is the largest q-conditioning. The required `name` parameter is never defined, leaving the most important input ambiguous. The description adds partial meaning but does not fully compensate for the absent schema descriptions.

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 names the specific resource — Jenkins and Alavi's (1981) two identifications as matrices — and explains the two methods (prewhitened and non-prewhitened correlation/partial correlation matrices). It also distinguishes itself from the sibling identify_cross by stating it complements the pairwise CCFs. The purpose is clear to a knowledgeable reader, though the opening phrase is a label rather than a verb-driven statement.

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

Usage Guidelines2/5

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

The description describes the two methods in detail but never explicitly says when an agent should choose this tool over alternatives such as identify_cross or identify_echelon. The only usage hint is 'Complements identify_cross (the pairwise CCFs),' which is a relationship, not a decision rule. No prerequisites or exclusions are given.

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