Obsidian Diary MCP Server

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

With no annotations provided, the description carries full burden. It discloses that the tool saves entries and automatically adds backlinks, which are behavioral traits. However, it doesn't mention permission requirements, whether it overwrites existing entries, rate limits, or error conditions.

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 appropriately sized with clear sections (purpose, args, returns). The first sentence states the core functionality, and subsequent sections provide necessary details. However, the 'Args' and 'Returns' headings could be more integrated with the flow.

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 2 parameters with 0% schema coverage and an output schema exists, the description provides adequate context. It explains the tool's purpose, parameter formats, and return value expectations. The output schema means the description doesn't need to detail return structure, but it could better address behavioral aspects given no annotations.

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?

Schema description coverage is 0%, so the description must compensate. It provides format guidance for the date parameter ('YYYY-MM-DD format') and clarifies that 'content' is 'The diary entry content', adding meaningful context beyond the bare schema. However, it doesn't explain constraints like content length or date validation.

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 'Save' and resource 'diary entry', and adds 'automatically add relevant backlinks' which distinguishes it from basic creation tools. However, it doesn't explicitly differentiate from sibling tools like 'create_diary_template' or 'update_entry_backlinks'.

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?

No guidance is provided about when to use this tool versus alternatives like 'create_diary_template' or 'update_entry_backlinks'. The description only states what the tool does, not when it's appropriate compared to sibling tools.

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