Plane MCP

add_comment

Add a comment to a work item using HTML, with options for internal or external visibility.

Instructions

Add a comment to a work item. comment_html accepts HTML, e.g. 'Looks good'. access: INTERNAL or EXTERNAL.

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": {
      "issue_id": "<issue_id>",
      "comment_html": "<comment_html>"
    },
    "name": "add_comment"
  }
}

Input Schema

Name	Required	Default
`access`	No	INTERNAL
`issue_id`	Yes
`project_id`	No
`comment_html`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 6, 2026

TDQS

B3.1/5.0

Behavior2/5

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

With no annotations, the description must carry the full burden of behavioral disclosure, but it only mentions that comment_html supports HTML and access has two values. It does not disclose side effects, permission requirements, reversibility, or expected response, leaving significant behavioral traits undisclosed.

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?

The description is concise, front-loaded with the action, and includes a concrete HTML example plus valid access values. Every sentence adds useful information without waste.

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

Completeness2/5

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

For a mutation tool with no annotations, the description is too sparse to fully support invocation. It lacks context about the outcome, potential errors, or workflow fit, though an output schema exists. The tool is simple, but the description still leaves gaps around required parameters like issue_id and project_id.

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 description coverage is 0%, so the description must compensate. It explains comment_html and access, but leaves issue_id and project_id unexplained. While issue_id is relatively self-explanatory, project_id's purpose and default behavior are not clarified, providing only partial compensation.

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?

The description clearly states the action 'Add a comment' and the target 'a work item', which is specific and distinguishes it from sibling tools like update_comment and list_comments. The verb-resource pairing is unambiguous.

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?

No guidance is given on when to use this tool versus alternatives like update_comment or list_comments. The description provides parameter examples but does not mention any conditions, prerequisites, or alternative scenarios, so it offers no decision support.

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