update_frontmatter

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

With no annotations, the description carries the full burden. It discloses key behaviors (merge, replace, null-removal) which are central to the tool's operation. It does not mention return values or error handling, but provides substantial context beyond a bare mutation statement.

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, front-loaded with the main purpose and followed by concise behavioral modifiers. Every sentence contributes meaningful information with no redundancy.

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?

The description covers the core functionality (merge/replace/remove) adequately for a tool of this complexity. However, it does not specify return value or failure behaviors, and with no output schema or annotations, these gaps leave some uncertainty. Overall, it is largely complete for typical use.

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 coverage is 100%, so baseline is 3. The description adds the semantics that setting a value to null removes the field, which is not present in the schema's description for the 'updates' parameter. This enriches parameter understanding beyond the schema.

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 (update), the resource (YAML frontmatter of a note), and adds behavioral nuance (merge vs replace). It distinguishes from siblings like update_note and remove_frontmatter_field by specifying frontmatter-specific operations.

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 context on merge/replace behavior and null-removal, but does not explicitly guide when to use this tool over specialized siblings like remove_frontmatter_field or update_note. The usage is implied rather than explicitly contrasted.

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