ynab_tool_indexDiscovers available YNAB tool names for budget, transaction, review, approval, and cleanup operations so users can identify the right action to run.
Discover tool names for budget, transaction, review, approval and cleanup operations.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v6.1.0Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"Output schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v5.4.0Output schema / properties / result / descriptionRemoved value: -"Structured result returned by YNAB Tool Index."v5.1.1Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "result": {
+ "description": "Structured result returned by YNAB Tool Index."
+ }
+ },
+ "required": [
+ "result"
+ ],
+ "type": "object"
+}v3.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds essentially no behavioral context beyond the annotations: it doesn't say the response is a catalog, whether it's static or filtered, or that it takes no inputs and costs a round trip. Given an output schema exists, some latitude is warranted, but nothing here tells the agent how the tool behaves differently from a plain list.
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?
A single front-loaded sentence with no filler, which is right for an index tool. It is arguably too thin rather than bloated, but the structure itself is clean.
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 zero-param discovery tool whose entire value is routing the agent to the right sibling, the description omits the one thing that matters: that the returned names are consumed by ynab_tool_execute. With a large sibling list and an output schema, the definition is structurally fine but functionally under-explained.
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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-param tool applies. No parameter-related gaps.
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 gives a verb ('Discover') and the object ('tool names'), so the agent knows this is a discovery/index tool rather than a data operation. But 'budget, transaction, review, approval and cleanup operations' is a loose keyword list, and it never clarifies the relationship to the obviously paired sibling ynab_tool_execute, nor what form the discovered names take.
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 statement of when to call this versus the ~40 concrete siblings, and no mention that results are presumably meant to be fed into ynab_tool_execute. The agent must infer the entire discovery-then-execute workflow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.