set_frontmatter_property

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

With no annotations provided, the description carries the full burden. It discloses the create-if-missing behavior, which is valuable. However, it does not mention that setting a value overwrites an existing property, that null removes the property (though the schema covers this), or any side effects such as file modification permissions. This is partial coverage.

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 sentences and exactly as long as needed. It front-loads the core action and adds one key behavioral detail with zero waste.

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 setter with no output schema and full parameter coverage in the schema, the description is mostly complete. It conveys the essential behavior (single property, create if missing). It could be more complete by mentioning overwrite semantics or return behavior, but given the simplicity and schema richness, it is adequate.

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 input schema covers 100% of parameters with descriptions, so the baseline is 3. The tool description adds no additional parameter-specific meaning beyond what the schema already provides. The schema's value description includes the null-to-remove behavior, which the description does not mention.

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 action ('Set a single frontmatter property in a note') with a specific verb and resource. The qualifier 'single' distinguishes it from sibling tools like update_frontmatter, and the additional phrase 'Creates the property if it doesn't exist' adds behavioral clarity.

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 implies when to use the tool (when setting exactly one property, and it can create if missing) without explicitly naming alternatives or exclusions. The 'single' qualifier provides clear context but does not mention 'update_frontmatter' or other related tools, so it falls short of a 5 but is above minimal guidance.

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