Read note frontmatter (full or single key)

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

Annotations already declare readOnlyHint and idempotentHint, so the description's 'Read-only' confirms. It adds behavioral details: returns full frontmatter object without 'key' and just the field value with 'key'. This goes beyond annotations by clarifying conditional behavior.

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 two concise sentences, front-loaded with the main purpose, and no redundant words. It efficiently conveys the core behavior and condition.

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 simple read tool with full annotations and 100% parameter documentation, the description is sufficient. It explains what is returned and the key behavior. No output schema exists, but the return type can be inferred. Could benefit from mentioning possible return types (object or scalar), but not a critical gap.

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?

All three parameters (key, path, title) have descriptions in the schema, achieving 100% coverage. The description adds meaning by explaining how the 'key' parameter affects output (returns field value vs full object). This is extra value beyond the schema's basic descriptions.

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 returns parsed YAML frontmatter for a note, with distinction between returning full object versus a single key. It uses specific verb 'Return' and identifies the resource 'frontmatter'. It implicitly differentiates from sibling tools like obsidian_frontmatter_search (search) and obsidian_read_note (full note), though not explicitly.

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 explicit guidance on when to use this tool versus alternatives like obsidian_read_note for full note content or obsidian_frontmatter_search for searching. However, its behavior is intuitive for reading frontmatter, and the 'Read-only' annotation hints at safe usage. Implied usage is adequate.

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