DuDuClaw

Overview Schema Source Related Servers Discussions Admin

memory_get_history

Read-only

Retrieve every value a subject-predicate fact has held, oldest to newest, including expired entries and superseding writes. Use it to audit how a fact changed over time.

Instructions

Every value a (subject, predicate) fact has had, oldest to newest, expired rows included, showing which write superseded which. For the value at one instant use memory_get_at.

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": {
      "subject": "<subject>",
      "predicate": "<predicate>"
    },
    "name": "memory_get_history"
  }
}

Input Schema

Name	Required	Description	Default
`subject`	Yes	The triple subject (e.g. 'user:main', 'person:me')
`predicate`	Yes	The triple predicate (e.g. 'prefers_language', 'spouse')

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.73.3Oct 15, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds real behavioral detail beyond them: expired rows are included, results are ordered oldest to newest, and the supersession chain between writes is exposed. It does not mention result size limits or pagination for long histories.

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 sentences, no filler, and the most decision-relevant content (what is returned, including expired rows) is front-loaded before the alternative-tool pointer.

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

Completeness4/5

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

With no output schema and a safe read operation, the description does the work of explaining the returned sequence, its ordering and its supersession semantics. Only the absence of any volume/pagination note for potentially long histories keeps it from being fully complete.

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 100% and both parameters are documented with examples in the schema, so the description carries no extra parameter burden. It frames the two params as a fact pair but adds no syntax or format meaning beyond the schema.

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

Purpose5/5

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

States a specific verb/resource: it returns the full historical sequence of values for a (subject, predicate) fact. It also explicitly differentiates itself from the sibling memory_get_at, which covers the point-in-time case.

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

Usage Guidelines5/5

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

Directly routes the agent: 'For the value at one instant use memory_get_at,' which tells the agent when to pick the sibling over this tool. The condition selecting each tool is stated rather than implied.

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