PerMark

open

Idempotent

Displays a PerMark document at a specified line or heading without stealing focus, launching the app if it is closed.

Instructions

Show the person a document in PerMark (line or heading) without taking focus; starts PerMark if closed.

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": {
      "path": "<path>"
    },
    "name": "open"
  }
}

Input Schema

Name	Required	Description
`line`	No	Line from 1.
`path`	Yes	Project-relative path.
`heading`	No	Heading or path `A > B`.

Schema Changelog

Changes observed during successful MCP inspections.

Changed9 schema fields changedv0.7.0Oct 23, 2026

removedInput schema / $schema

Removed value: -"https://json-schema.org/draft/2020-12/schema"

addedInput schema / additionalProperties
```
Added value: +false
```

changedInput schema / properties / heading / description

Previous value: -"A heading of the document to show, such as `Rollout`, or a path of headings such as `Plan > Rollout`.\nWins over `line` when the document has it. Optional."New value: +"Heading or path `A > B`."

changedInput schema / properties / heading / type

Previous value: -[
-  "string",
-  "null"
-]New value: +"string"

changedInput schema / properties / line / description

Previous value: -"A line of the document to show (from 1). Optional."New value: +"Line from 1."

removedInput schema / properties / line / format
```
Removed value: -"uint32"
```
changedInput schema / properties / line / minimum
```
Previous value: -0New value: +1
```

changedInput schema / properties / line / type

Previous value: -[
-  "integer",
-  "null"
-]New value: +"integer"

changedInput schema / properties / path / description

Previous value: -"The document, relative to the project folder, with `/` separators (for example `docs/plan.md`)."New value: +"Project-relative path."

First observedv0.1.0Oct 17, 2026

TDQS

A3.8/5.0

Behavior4/5

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

Annotations already specify that the tool is non-destructive, idempotent, and not read-only. The description adds meaningful behavioral context by disclosing that it may start PerMark and deliberately avoids taking focus.

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 definition is a single, front-loaded sentence with no wasted words. The key behavior—showing a document without taking focus—is stated immediately.

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?

All three parameters are documented in the schema, and the description covers the important non-obvious effects: auto-launching and not stealing focus. With no output schema, no return-value explanation is needed.

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%, so the parameter meanings are already fully documented. The description only parenthetically mentions line or heading and adds no new syntax or semantics beyond the schema.

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 uses a specific verb, "Show," and identifies the resource as a document in PerMark, including line/heading positioning. It clearly conveys the UI-opening behavior, but does not explicitly distinguish the tool from the sibling `read` tool.

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

Usage Guidelines3/5

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

It gives useful conditions such as starting PerMark if closed and not taking focus, but does not state when to choose this over `read` or other document-access siblings. Usage is implied rather than explicitly guided.

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

Deploy Server