Obsidian MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('write or update') but lacks critical details: it doesn't specify if this overwrites existing files, requires authentication, has rate limits, or handles errors. For a mutation tool with zero annotation coverage, this is a significant gap in transparency.

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 and front-loaded in a single sentence that directly states the tool's purpose. There is no wasted language or unnecessary elaboration, making it efficient and easy to parse at a glance.

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 tool's complexity (a mutation operation with 6 parameters, no annotations, and no output schema), the description is insufficiently complete. It doesn't cover behavioral aspects like side effects, error handling, or return values, leaving the agent with critical gaps in understanding how to use the tool effectively.

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 adds no parameter-specific information beyond what's already in the schema, which has 100% coverage. It doesn't explain the semantics of parameters like 'frontmatter' (e.g., its format or use cases) or 'expectedModTime' (e.g., how conflict detection works). With high schema coverage, the baseline is 3, as the description doesn't compensate with extra insights.

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 clearly states the verb ('write or update') and resource ('a file in a vault'), making the purpose unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'append_content' (which might modify existing files differently) or 'get_file' (which reads files), missing full sibling distinction for a perfect score.

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. For example, it doesn't mention when to choose 'write_file' over 'append_content' for modifying files, or prerequisites like needing write access to the vault. This lack of contextual direction leaves usage unclear.

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