irs-taxpayer-mcp

Overview Schema Source Related Servers Discussions Admin

estimate_quarterly_tax

Read-onlyIdempotent

Calculate Form 1040-ES estimated quarterly tax payments for self-employed taxpayers by entering expected annual income, filing status, W-2 withholding, and self-employment income to avoid underpayment penalties.

Instructions

Calculate estimated quarterly tax payments (Form 1040-ES) for self-employed or other taxpayers who need to make estimated payments.

Input Schema

TableJSON Schema

Name	Required	Description
`taxYear`	Yes	Tax year
`filingStatus`	Yes
`otherCredits`	No	Expected other tax credits
`w2Withholding`	No	Expected total W-2 tax withholding for the year
`expectedAnnualIncome`	Yes	Expected total annual income
`selfEmploymentIncome`	No	Expected self-employment income

Output Schema

TableJSON Schema

Name	Required	Description	Default
`text`	Yes
`error`	No
`isError`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.0.1Sep 7, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "error": {
+      "additionalProperties": false,
+      "properties": {
+        "code": {
+          "type": "string"
+        },
+        "message": {
+          "type": "string"
+        },
+        "suggestion": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "code",
+        "message",
+        "suggestion"
+      ],
+      "type": "object"
+    },
+    "isError": {
+      "type": "boolean"
+    },
+    "text": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "text",
+    "isError"
+  ],
+  "type": "object"
+}

First observedv0.5.3Feb 25, 2026

TDQS

A3.5/5.0

Behavior3/5

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

Annotations already cover read-only, idempotent, non-destructive behavior, so the description only adds context about Form 1040-ES and the target taxpayer. It does not disclose assumptions, calculation approach, or limitations such as whether underpayment penalties or safe harbor rules are considered. This is acceptable but not rich.

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 a single, focused sentence with the core action front-loaded. It avoids redundancy and wasted words, while still conveying the purpose and target users.

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

Completeness3/5

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

With an output schema and annotations present, the description provides a minimum viable explanation. However, it lacks guidance on how this tool differs from close siblings like estimate_self_employment_tax or calculate_total_tax, and it does not mention whether the result is an estimated amount per quarter or an annual total. Slightly more context would improve confidence for an agent deciding among similar tools.

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?

Schema description coverage is 83%, so most parameters are already documented in the schema. The description loosely adds meaning by tying 'self-employed' to selfEmploymentIncome and 'expected' income to expectedAnnualIncome, but it does not explain relationships between parameters or any special requirements beyond the schema.

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?

The description states a specific action ('Calculate estimated quarterly tax payments'), names a concrete resource (Form 1040-ES), and identifies the target audience. It does not explicitly contrast itself with siblings like estimate_self_employment_tax or calculate_total_tax, so it stops short of full differentiation.

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

Usage Guidelines3/5

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

The description implies when to use the tool ('for self-employed or other taxpayers who need to make estimated payments'), which gives clear context. However, it does not explicitly state when not to use it or name alternative tools for related calculations, such as calculate_total_tax or estimate_self_employment_tax.

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

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