Obsidian MCP Server

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

The description adds valuable behavioral context beyond the openWorldHint annotation. It explains that existing properties with the same key will be overwritten, describes the return value structure with examples, mentions environment setup requirements (Obsidian Vault path), and specifies dependencies on generate_obsidian_properties output. While it doesn't cover rate limits or error conditions, it provides substantial operational context.

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 with clear sections (Description, Parameters, Return Value, Dependencies & Requirements), but contains some redundancy. The 'Description:' label is repeated, and the examples are quite detailed. While informative, it could be more concise by eliminating the redundant labeling and tightening some explanations.

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 mutation tool with openWorldHint annotation and no output schema, the description provides good contextual completeness. It explains the tool's relationship to other tools, includes return value examples, specifies environment requirements, and describes the overwrite behavior. The main gap is lack of explicit error handling information, but overall it's quite comprehensive for the tool's complexity.

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 100% schema description coverage, the input schema already thoroughly documents all parameters. The description adds minimal value beyond the schema - it provides examples for filePath and properties parameters, but doesn't explain parameter semantics or constraints that aren't already in the schema descriptions. The baseline of 3 is appropriate when the schema does the heavy lifting.

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 ('adds or updates properties') and resources ('within the frontmatter section at the top of a specified Obsidian markdown file'). It distinguishes from sibling tools by explicitly mentioning its relationship to 'generate_obsidian_properties' and specifying it's for applying metadata to actual files, unlike create_document_with_properties which likely creates new documents.

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 clear context for when to use this tool ('primarily used to apply metadata generated by the generate_obsidian_properties tool') and mentions environment requirements. However, it doesn't explicitly state when NOT to use it or provide detailed alternatives among sibling tools like create_document_with_properties.

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