set_frontmatterMerge new or updated keys into a markdown note's frontmatter. Pass a null value to delete an existing key.
Merge keys into frontmatter (null value deletes a key).
| Name | Required | Description | Default |
|---|---|---|---|
| note_id | Yes | ||
| updates | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the burden of behavioral disclosure. It does reveal the key behavioral nuance: the operation merges rather than replaces, and a null value deletes a key. However, it does not disclose whether existing keys are overwritten, how nested objects are handled, error behavior, or any permission requirements.
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 a single sentence with no wasted words. The main action is front-loaded, and the parenthetical efficiently captures the deletion behavior without adding bulk.
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?
With an output schema present and only two parameters, the core invocation details are sufficient. However, the arbitrary 'updates' object leaves ambiguity about accepted value types, shallow versus deep merge behavior, and validation failure handling, so the description is not fully complete for all realistic agent scenarios.
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 explains that 'updates' is a set of frontmatter keys to merge and that null values delete keys, which adds real meaning beyond the raw schema. It does not specify the format or type of 'note_id', but the name and string type are largely self-explanatory.
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 uses a specific verb, 'merge', tied to a specific resource, 'frontmatter', and adds the key deletion rule for null values. It is not a tautology and clearly differentiates from 'get_frontmatter', though it does not explicitly contrast with sibling mutation tools like 'patch_note' or 'update_note'.
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?
There is no explicit guidance about when to use this tool versus alternatives such as 'patch_note', 'update_note', or 'get_frontmatter'. The intended context is only implied by the word 'frontmatter', with no stated prerequisites, exclusions, or comparison to siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.