Obsidian MCP Server

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

The description adds significant behavioral context beyond annotations, explaining the four distinct modes with their specific behaviors (e.g., CREATE is safe, OVERWRITE replaces entire file). Annotations provide basic hints (readOnlyHint=false, destructiveHint=false), but the description elaborates on operational details like default modes and safety characteristics, though it doesn't cover rate limits or auth needs.

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 well-structured and concise, with clear sections (purpose, modes, args, returns, example) and no wasted sentences. Each sentence adds value, such as explaining modes and providing a practical example, making it easy to scan and understand.

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 (multiple modes, 1 parameter with nested object) and the presence of an output schema (returns str), the description is largely complete. It covers purpose, usage, parameters, and behavior, though it could benefit from more detail on error cases or frontmatter handling. The output schema reduces the need to explain return values.

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 some parameter semantics by listing and briefly describing the four parameters (filepath, content, mode, frontmatter) and providing an example. However, with 0% schema description coverage, the schema lacks descriptions, so the description partially compensates but doesn't fully detail formats or constraints (e.g., filepath structure, content limits).

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 tool's purpose with specific verbs ('Create or modify notes') and resources ('notes with content and optional frontmatter'), distinguishing it from siblings like obsidian_append_content by covering multiple modes. It explicitly identifies itself as the 'Primary tool for Zettelkasten note creation,' providing clear differentiation.

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 explicit usage guidelines by detailing four specific modes (CREATE, OVERWRITE, APPEND, PREPEND) with clear behavioral descriptions, including safety notes ('safe, won't overwrite' for CREATE). It distinguishes when to use this tool versus alternatives like obsidian_append_content by offering a comprehensive set of write operations in one tool.

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