ExpenseBot

whatif_afford

Read-only

Can I afford $X/month? Recomputes the user's Safe Monthly Draw (how much they can safely pay themselves) with an added recurring monthly cost, and returns a yes/tight/no verdict plus the before/after numbers. Use for questions like 'can I afford a $500/mo hire' or 'what if I add a $200/mo software subscription'. Requires at least 3 months of income history — otherwise returns insufficient_data rather than a guess.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`deltaMonthly`	Yes	The new recurring monthly cost being considered, in the user's home currency

Output Schema

TableJSON Schema

Name	Required	Description
`data`	No	The full what-if scenario: assumptions, evidence, and computed outcome.
`message`	No	Scenario narrative; may be absent if the scenario carried no template or evidence.
`success`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedSep 9, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": true,
+  "properties": {
+    "data": {
+      "additionalProperties": true,
+      "description": "The full what-if scenario: assumptions, evidence, and computed outcome.",
+      "type": "object"
+    },
+    "message": {
+      "description": "Scenario narrative; may be absent if the scenario carried no template or evidence.",
+      "type": "string"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success"
+  ],
+  "type": "object"
+}

Changed1 schema field changedAug 25, 2026

changedOutput schema / (root)

Previous value: -{
-  "additionalProperties": true,
-  "description": "Standard ExpenseBot tool result envelope. `message` is the human-readable summary the AI cites; `data` is the structured payload (totals, breakdowns, ids, etc.). On failure, `success` is false and `error` carries a code/message/hint triple.",
-  "properties": {
-    "data": {
-      "additionalProperties": true,
-      "description": "Structured payload. Shape varies per tool — common keys: total, breakdown, comparison, sampleMeta, ids, expenseId, reportId, signupUrl, results.",
-      "type": "object"
-    },
-    "error": {
-      "additionalProperties": true,
-      "description": "Present only when success === false.",
-      "properties": {
-        "code": {
-          "type": "string"
-        },
-        "hint": {
-          "type": "string"
-        },
-        "message": {
-          "type": "string"
-        }
-      },
-      "type": "object"
-    },
-    "message": {
-      "description": "Human-readable result text. Always present on success; prefer rendering this verbatim before any further reasoning.",
-      "type": "string"
-    },
-    "sampleMeta": {
-      "additionalProperties": true,
-      "description": "Set when the underlying dataset was truncated. isTruncated=true means the agent saw a sample of `sampleCount` of `totalCount` rows; aggregate totals are still accurate.",
-      "properties": {
-        "isTruncated": {
-          "type": "boolean"
-        },
-        "sampleCount": {
-          "type": "integer"
-        },
-        "totalCount": {
-          "type": "integer"
-        }
-      },
-      "type": "object"
-    },
-    "success": {
-      "description": "False on tool errors; check before reading `data`.",
-      "type": "boolean"
-    }
-  },
-  "type": "object"
-}New value: +null

First observedAug 10, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already mark readOnlyHint=true and destructiveHint=false, so the read-only nature is covered. The description adds noteworthy behavioral detail beyond annotations: the requirement of at least 3 months of income history and the insufficient_data non-guess response, which helps an agent anticipate edge conditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences: a functional summary with output types, a practical use-case framing, and a key prerequisite/edge behavior. Every sentence has value, the most important facts are front-loaded, and nothing is redundant or verbose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the single param, full schema coverage, non-destructive readOnly annotations, and the presence of an output schema, this description covers the tool's purpose, prerequisites, behavior, and result shape. No significant information an agent needs to select or invoke it is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema covers the single parameter completely with a clear description, including minimum value and currency context. The tool description adds no new parameter-specific information since 100% of the schema is already described, so the baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states it recomputes the user's Safe Monthly Draw with an added monthly cost and returns a yes/tight/no verdict plus before/after numbers. It does not explicitly name or differentiate the whatif_client and whatif_tax_setaside siblings, but the affordability context is specific enough.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides concrete usage examples like 'can I afford a $500/mo hire' and mentions a precondition (3 months of income history) including the failure mode (returning insufficient_data). It does not give an explicit when-not or alternative tool recommendation among the siblings, so it stops short of a 5.

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

All ExpenseBot tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.