get_categoryRetrieve current-month category details and goal fields from a YNAB budget; use the month-specific tool for other months.
Get current-month category detail and goal fields. For other months use get_month_category.
| Name | Required | Description | Default |
|---|---|---|---|
| budgetId | No | ||
| categoryId | Yes | Category ID |
| 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"Input schema / properties / budgetId / descriptionRemoved value: -"Budget ID (uses default if not provided)"Output schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v5.4.0Output schema / properties / result / descriptionRemoved value: -"Structured result returned by Get Category."v5.1.1Output schema / (root)Previous value: -nullNew value: +{
+ "$schema": "http://json-schema.org/draft-07/schema#",
+ "additionalProperties": false,
+ "properties": {
+ "result": {
+ "description": "Structured result returned by Get Category."
+ }
+ },
+ "required": [
+ "result"
+ ],
+ "type": "object"
+}v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so safety behaviour is fully covered. The description adds genuine context beyond that by scoping the read to the current month and noting that goal fields are returned. It says nothing about budget-scoping or missing-category behaviour, so it is additive but modest.
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?
Two short sentences, front-loaded with what the tool returns and immediately followed by the routing rule. No filler and no repetition of the title.
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, the description is not obliged to explain return values, and the current-month vs. other-month distinction is the key thing an agent needs. However, the optional budgetId and its default resolution are unaddressed, leaving a real gap for a tool that can be scoped to a specific budget.
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 50%, and the one documented parameter's description is a tautology ("Category ID"). The optional budgetId is undocumented in both schema and description, and the description never mentions either parameter, so it does nothing to compensate for the coverage gap — notably, what happens when budgetId is omitted is left entirely unexplained.
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?
Specific verb (Get) plus resource (category detail and goal fields) with an explicit temporal scope (current-month). It names the sibling it must not be confused with, get_month_category, so an agent can distinguish the two without opening either schema.
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?
"For other months use get_month_category" gives an explicit routing rule to the alternative for the main branching case. It stops short of covering other adjacency questions (e.g., search_categories for lookup by name, or whether budgetId defaults to the last-used budget), so it is clear but not exhaustive.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.