Open an existing design document by absolute path, or retrieve it if already open. Respects configured readable folders, with Desktop allowed by default.
Open an existing document from an absolute path (or return it if it is already open). Affinity's filesystem setting limits which folders are readable; the Desktop is allowed by default.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations, it discloses the already-open behavior and a non-obvious filesystem restriction, including that Desktop is readable by default. It does not explain errors for inaccessible or invalid paths, but it provides meaningful operational context for a simple tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences front-load the operation and then state the key filesystem constraint. There is no filler or unnecessary repetition of structured fields.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a one-parameter tool, it covers the main operation, duplicate-open behavior, and principal access restriction. Sibling disambiguation and error or return details remain absent, but the description is sufficient for correct basic invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 0% schema description coverage, the description usefully explains that path must be absolute, identify an existing document, and reside in a readable location. The Desktop default adds concrete guidance, although an example path or supported-file guidance could help further.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific verb and resource: opening an existing document from an absolute path. "Existing" helps distinguish it from affinity_new_document, but it does not clarify how this tool differs from the similarly named affinity_open sibling.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
It provides clear usage context: supply an absolute path to an existing document, and an already-open document is simply returned. It does not name alternatives or explain when affinity_open should be preferred.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.