mcp-obsidian

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 tool modifies notes ('set or update'), implying mutation, but doesn't cover permissions, error handling, or response format. It adds some context about creating frontmatter if absent, but for a mutation tool with zero annotation coverage, this is insufficient.

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 and front-loaded: the first sentence states the core purpose, followed by a structured 'Args' section. Each sentence adds value, with no wasted words. It could be slightly more concise by integrating the examples into the main text, but overall it's efficient.

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 (mutation with 3 parameters), no annotations, and an output schema (which reduces the need to explain return values), the description is moderately complete. It covers the purpose and parameters well but lacks usage guidelines and behavioral details like error cases or side effects, leaving gaps for an AI agent.

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 significant meaning beyond the input schema, which has 0% description coverage. It explains each parameter: 'path' as 'Relative path to the note', 'key' as 'Frontmatter key to set (e.g. 'status', 'tags')', and 'value' with examples for lists. This compensates well for the schema's lack of documentation, though it doesn't cover all edge cases.

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: 'Set or update a frontmatter field in a note. Creates frontmatter if absent.' It specifies the verb ('set or update'), resource ('frontmatter field in a note'), and scope ('creates frontmatter if absent'). However, it doesn't explicitly differentiate from sibling tools like 'write_note' or 'append_to_note', which might also modify notes, keeping it from 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. It doesn't mention sibling tools like 'write_note' (which might handle broader note updates) or 'get_frontmatter' (for reading), nor does it specify prerequisites or exclusions. Usage is implied by the purpose but lacks explicit context.

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