Excaliself

Reply to comment

reply_to_comment

Adds a plain-text reply to an open Excalidraw comment thread; reopen resolved threads first. Use it to answer or continue drawing discussions with teammates.

Instructions

Adds a comment to an open thread. A resolved thread must be reopened first (resolve_comment with resolved: false).

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": {
      "threadId": "<threadId>",
      "body": "<body>"
    },
    "name": "reply_to_comment"
  }
}

Input Schema

Name	Required	Description	Default
`body`	Yes	Plain text, up to 2000 characters. No Markdown.
`threadId`	Yes	A threadId from list_comments.

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.11.0Nov 10, 2026

TDQS

A3.8/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the write/safety profile is covered. The description adds real behavioral context beyond the annotations: the operation is gated on thread resolution state and what to do about it. It does not cover permissions or error behavior, but that is a modest omission for a simple comment-append.

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

Conciseness4/5

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

Two sentences, front-loaded with the core action, and the precondition sentence includes a concrete remedy rather than a vague warning. No filler.

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?

A simple two-parameter mutation whose required fields and text constraints are fully documented in the schema, and the key state precondition is stated. What remains missing is differentiation from the sibling add_comment and any indication of success/failure behavior, leaving a moderate gap.

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%, with threadId tied to list_comments and body constrained to plain text up to 2000 characters. The description adds no parameter meaning beyond the schema, so baseline 3 is appropriate.

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?

States a specific verb and resource ('Adds a comment') plus a scope constraint ('to an open thread'), which distinguishes it from a create-thread tool. It does not explicitly contrast with the sibling add_comment, so full differentiation must be inferred.

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

Usage Guidelines4/5

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

Gives an explicit precondition for use — the thread must be open — and names the prerequisite action (resolve_comment with resolved: false) with the exact argument. It does not say when to prefer this over add_comment.

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