Utility Matrix

SLO Burn Rate Calculator

slo-burn-rate-calculator

Read-onlyIdempotent

Use this when a user asks how fast they are burning their error budget, or whether their current error rate will exhaust their SLO window. Takes error count, total requests, SLO target, and observation window. Returns burn rate and budget consumption per hour.

Input Schema

Name	Required	Description
`slo`	Yes	Service-level objective target expressed as a percentage.
`total`	Yes	Total number of requests observed in the measurement window.
`errors`	Yes	Number of failed requests observed in the measurement window.
`window_hours`	Yes	Length of the observed measurement window in hours.

Output Schema

Name	Required	Description	Default
`status`	Yes
`burn_rate`	Yes
`next_step`	Yes
`window_hours`	Yes
`next_step_url`	Yes
`why_follow_up`	Yes
`error_rate_pct`	Yes
`interpretation`	Yes
`affiliate_context`	No
`computation_basis`	Yes
`budget_consumed_pct_per_hour`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed11 schema fields changedSep 28, 2026

addedInput schema / properties / errors / description

Added value: +"Number of failed requests observed in the measurement window."

addedInput schema / properties / errors / examples
```
Added value: +[
+  1
+]
```

addedInput schema / properties / slo / description

Added value: +"Service-level objective target expressed as a percentage."

addedInput schema / properties / slo / examples
```
Added value: +[
+  1
+]
```

addedInput schema / properties / total / description

Added value: +"Total number of requests observed in the measurement window."

addedInput schema / properties / total / examples
```
Added value: +[
+  1
+]
```

addedInput schema / properties / window_hours

Added value: +{
+  "description": "Length of the observed measurement window in hours.",
+  "examples": [
+    1
+  ],
+  "minimum": 1,
+  "type": "number"
+}

changedInput schema / required

Previous value: -[
-  "errors",
-  "total",
-  "slo"
-]New value: +[
+  "errors",
+  "total",
+  "slo",
+  "window_hours"
+]

addedOutput schema / properties / computation_basis
```
Added value: +{
+  "type": "string"
+}
```
addedOutput schema / properties / window_hours
```
Added value: +{
+  "type": "number"
+}
```

changedOutput schema / required

Previous value: -[
-  "budget_consumed_pct_per_hour",
-  "burn_rate",
-  "error_rate_pct",
-  "interpretation",
-  "next_step",
-  "next_step_url",
-  "status",
-  "why_follow_up"
-]New value: +[
+  "budget_consumed_pct_per_hour",
+  "burn_rate",
+  "computation_basis",
+  "error_rate_pct",
+  "interpretation",
+  "next_step",
+  "next_step_url",
+  "status",
+  "why_follow_up",
+  "window_hours"
+]

Changed1 schema field changedJul 15, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": false,
+  "properties": {
+    "affiliate_context": {
+      "additionalProperties": false,
+      "properties": {
+        "affiliate": {
+          "type": "string"
+        },
+        "cta_label": {
+          "type": "string"
+        },
+        "disclosure": {
+          "type": "string"
+        },
+        "framing": {
+          "type": "string"
+        },
+        "posture": {
+          "enum": [
+            "secondary"
+          ],
+          "type": "string"
+        },
+        "slot_id": {
+          "type": "string"
+        },
+        "url": {
+          "type": "string"
+        },
+        "variant": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "affiliate",
+        "cta_label",
+        "disclosure",
+        "framing",
+        "posture",
+        "slot_id",
+        "url",
+        "variant"
+      ],
+      "type": "object"
+    },
+    "budget_consumed_pct_per_hour": {
+      "type": "number"
+    },
+    "burn_rate": {
+      "type": "number"
+    },
+    "error_rate_pct": {
+      "type": "number"
+    },
+    "interpretation": {
+      "type": "string"
+    },
+    "next_step": {
+      "type": "string"
+    },
+    "next_step_url": {
+      "type": "string"
+    },
+    "status": {
+      "type": "string"
+    },
+    "why_follow_up": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "budget_consumed_pct_per_hour",
+    "burn_rate",
+    "error_rate_pct",
+    "interpretation",
+    "next_step",
+    "next_step_url",
+    "status",
+    "why_follow_up"
+  ],
+  "type": "object"
+}

Changed1 schema field changedJul 13, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```
First observedJun 29, 2026

TDQS

A3.6/5.0

Behavior3/5

Does 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 agent knows this is a pure, side-effect-free computation. The description adds that it returns burn rate and hourly budget consumption, but that is already implied by the output schema and the name, so added behavioral context is thin.

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

Conciseness4/5

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

Two sentences, front-loaded with the trigger condition and followed by the computation. The closing sentence about returns largely duplicates the output schema, so it is slightly padded but still tight overall.

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

Completeness4/5

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

With full schema coverage, an existing output schema, and read-only annotations, the description covers everything needed to invoke the tool correctly. The one remaining gap is sibling differentiation (error-budget-calculator, availability-sla-calculator) in a large family of similar calculators.

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 100%, so every parameter (errors, total, slo, window_hours) is already documented in the schema. The description restates the input set without adding units, format, or constraints beyond it, so the baseline 3 applies.

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 computation (burn rate and error-budget consumption per hour) from named inputs, so the purpose is unambiguous. It does not, however, distinguish itself from the closely-related sibling error-budget-calculator, so it falls short of a 5.

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?

It gives explicit trigger conditions in user-intent terms: 'when a user asks how fast they are burning their error budget, or whether their current error rate will exhaust their SLO window.' That is a clear when-to-use, but no when-not-to-use and no routing to the sibling error-budget-calculator.

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

All Utility Matrix tools Inspect

Try in Browser

Shareable, User-Owned Context BackendPeople, applications, and agents read, write, and coordinate together in one context lake. Reach it over MCP, a CLI, a Python SDK, or REST.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?