mcp-memory-graph

core_memory_append

Appends text to the pinned core-memory block, newline-separated if non-empty. Refuses writes that exceed the character limit; use core_memory_replace to compact.

Instructions

Append text to the pinned core-memory block (newline-separated when non-empty). If the result would exceed char_limit the write is refused (error: core_memory_full) so you compact via core_memory_replace instead of silently overflowing.

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": {
      "text": "<text>"
    },
    "name": "core_memory_append"
  }
}

Input Schema

Name	Required	Description	Default
`scope`	No	Memory scope for isolation	global
`namespace`	No	Namespace within scope (e.g., project name, team name)
`text`	Yes	Text to append to the pinned core-memory block (newline-separated when the block is non-empty). Refused if it would exceed char_limit — compact via core_memory_replace instead.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.6.4Jun 17, 2026

TDQS

A4.6/5.0

Behavior4/5

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

Discloses refusal behavior on exceeding char_limit and suggests alternative. Lacks explicit mention of mutation or state change, but 'append' implies it. Annotations are minimal (only openWorldHint=false), so description adds useful behavioral context.

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, front-loaded purpose, no fluff. Every word contributes to understanding.

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?

Adequate for a simple append tool. Mentions error case but does not describe success return. No output schema, but for a tool with clear side effects, this is acceptable. Could mention success confirmation.

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?

Schema description coverage is 100%; description adds meaning beyond schema by explaining newline separation and the overflow condition. Enhances understanding of text parameter behavior.

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?

Clear verb 'Append' and resource 'pinned core-memory block', with specific detail 'newline-separated when non-empty'. Distinguishes from sibling core_memory_replace by mentioning the alternative for overflow.

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?

Explicitly states when to use: append text, and when not: if exceeding char_limit, use core_memory_replace instead. Also provides error condition 'core_memory_full'.

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

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