Filter Obsidian notes by YAML frontmatter properties to find entries matching equality, $in, $exists, or $contains conditions; combine multiple keys with AND.
Filter notes by their YAML frontmatter. Supports equality, $in, $exists, $contains predicates. Multiple keys are AND-combined.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| vault | Yes | ||
| where | Yes |
Changes observed during successful MCP inspections.
v2.5.0Input schema / properties / where / additionalProperties / anyOfPrevious value: -[
- {
- "type": "string"
- },
- {
- "type": "number"
- },
- {
- "type": "boolean"
- },
- {
- "type": "null"
- },
- {
- "properties": {
- "$in": {
- "items": {
- "anyOf": [
- {
- "type": "string"
- },
- {
- "type": "number"
- },
- {
- "type": "boolean"
- },
- {
- "type": "null"
- }
- ]
- },
- "type": "array"
- }
- },
- "required": [
- "$in"
- ],
- "type": "object"
- },
- {
- "properties": {
- "$exists": {
- "type": "boolean"
- }
- },
- "required": [
- "$exists"
- ],
- "type": "object"
- },
- {
- "properties": {
- "$contains": {
- "anyOf": [
- {
- "type": "string"
- },
- {
- "type": "number"
- },
- {
- "type": "boolean"
- },
- {
- "type": "null"
- }
- ]
- }
- },
- "required": [
- "$contains"
- ],
- "type": "object"
- }
-]New value: +[
+ {
+ "type": "string"
+ },
+ {
+ "type": "number"
+ },
+ {
+ "type": "boolean"
+ },
+ {
+ "type": "null"
+ },
+ {
+ "properties": {
+ "$in": {
+ "items": {
+ "type": [
+ "string",
+ "number",
+ "boolean",
+ "null"
+ ]
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "$in"
+ ],
+ "type": "object"
+ },
+ {
+ "properties": {
+ "$exists": {
+ "type": "boolean"
+ }
+ },
+ "required": [
+ "$exists"
+ ],
+ "type": "object"
+ },
+ {
+ "properties": {
+ "$contains": {
+ "type": [
+ "string",
+ "number",
+ "boolean",
+ "null"
+ ]
+ }
+ },
+ "required": [
+ "$contains"
+ ],
+ "type": "object"
+ }
+]v2.0.0-rc.5Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the description. The description adds the AND-combination behavior of multiple keys, which is genuinely useful, but says nothing about limits, result ordering, or behavior on unknown keys.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three tight sentences, each earning its place: purpose first, then predicate support, then combination semantics. Nothing redundant.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a nested-object query tool with no output schema and 0% schema coverage, the description covers the core filtering semantics but omits anything about the shape of results, how `limit` behaves, or what an empty/malformed `where` does. It is minimally sufficient rather than complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must carry parameter meaning. It does explain the predicate operators ($in, $exists, $contains) and equality, plus the AND semantics of the complex `where` object, which is the hardest parameter. However, `vault` and `limit` (with its default and cap) receive no explanation at all.
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?
States a specific verb and resource: 'Filter notes by their YAML frontmatter'. It is distinguishable from the search_* siblings in concept, but it never explicitly contrasts itself with search_text/search_semantic, so the division of labor is left implicit.
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 when-to-use guidance and no mention of alternatives, despite several plausible substitutes (search_text, search_semantic, search_hybrid, list_vaults) in the sibling set. The agent must infer that frontmatter-based filtering is the right choice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.