Obsidian MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Open a file' gives no information about what happens when a file is opened—does it require specific permissions, open in a new tab, modify the file, trigger side effects, or have rate limits? It doesn't even clarify if this is a read-only or mutative operation. For a tool with 4 parameters and no annotation coverage, this is completely inadequate.

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?

The description is extremely concise at just three words, which is efficient and front-loaded. However, it's arguably under-specified rather than appropriately concise—every word earns its place, but more words are needed to make the description useful. It lacks the structure to convey necessary details, though it doesn't waste space on redundancy.

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?

Given the complexity (4 parameters, no annotations, no output schema, and many sibling tools), the description is severely incomplete. It doesn't explain the tool's purpose beyond the name, provide usage context, describe behavior, or clarify parameters. For a tool that likely interacts with Obsidian vaults and files, this minimal description fails to equip an agent to use it correctly.

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?

The description mentions no parameters at all. With 4 parameters (vault, file, path, newtab) and 0% schema description coverage, the schema provides only titles without explanations. The description fails to compensate by explaining what these parameters mean, how they interact (e.g., file vs path), or what defaults apply. This leaves the agent guessing about required inputs and their purposes.

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 'Open a file' is a tautology that essentially restates the tool name 'obsidian_open' without adding meaningful specificity. It doesn't specify what type of file (e.g., Obsidian note, markdown file) or what 'open' means in this context (e.g., open in editor, open in viewer). While the verb 'open' is clear, the resource 'file' is too generic given the Obsidian context and sibling tools like obsidian_read, obsidian_create, and obsidian_append that handle files differently.

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?

The description provides no guidance on when to use this tool versus alternatives. With many sibling tools like obsidian_read (for reading file contents), obsidian_create (for creating files), and obsidian_workspace (for workspace operations), there's no indication of whether this tool opens files for editing, viewing, or another purpose. No context, exclusions, or alternatives are mentioned.

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