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assume

Read-onlyIdempotent

Add an assumption formula to an assume-guarantee contract, returning an abstraction that the original contract refines for verification.

Instructions

Add an assumption b to the contract: (b & A, b -> G). The result is an abstraction of the contract (it is refined by it).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "contract": "<contract>",
      "formula": "<formula>"
    },
    "name": "assume"
  }
}

Input Schema

Name	Required	Description	Default
`name`	No
`formula`	Yes
`contract`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.7.0Nov 2, 2026

addedInput schema / $defs / ContractSpec / properties / constants

Added value: +{
+  "additionalProperties": {
+    "anyOf": [
+      {
+        "type": "integer"
+      },
+      {
+        "type": "number"
+      }
+    ]
+  },
+  "description": "Named constants: name -> value; the formulas use the names (repair changes them)",
+  "title": "Constants",
+  "type": "object"
+}

Changed4 schema fields changedv0.4.2Oct 29, 2026

changedInput schema / $defs / ContractSpec / properties / inputs / additionalProperties / anyOf

Previous value: -[
-  {
-    "enum": [
-      "bool",
-      "real"
-    ],
-    "type": "string"
-  },
-  {
-    "maxItems": 2,
-    "minItems": 2,
-    "prefixItems": [
-      {
-        "type": "integer"
-      },
-      {
-        "type": "integer"
-      }
-    ],
-    "type": "array"
-  }
-]New value: +[
+  {
+    "enum": [
+      "bool",
+      "real"
+    ],
+    "type": "string"
+  },
+  {
+    "maxItems": 2,
+    "minItems": 2,
+    "prefixItems": [
+      {
+        "type": "integer"
+      },
+      {
+        "type": "integer"
+      }
+    ],
+    "type": "array"
+  },
+  {
+    "pattern": "^(signed |unsigned )?word\\[[1-9][0-9]*\\]$",
+    "type": "string"
+  }
+]

changedInput schema / $defs / ContractSpec / properties / inputs / description

Previous value: -"Input variables: \"bool\", [low, high], or \"real\""New value: +"Input variables: \"bool\", [low, high], \"real\", or \"word[n]\" (\"signed word[n]\")"

changedInput schema / $defs / ContractSpec / properties / outputs / additionalProperties / anyOf

Previous value: -[
-  {
-    "enum": [
-      "bool",
-      "real"
-    ],
-    "type": "string"
-  },
-  {
-    "maxItems": 2,
-    "minItems": 2,
-    "prefixItems": [
-      {
-        "type": "integer"
-      },
-      {
-        "type": "integer"
-      }
-    ],
-    "type": "array"
-  }
-]New value: +[
+  {
+    "enum": [
+      "bool",
+      "real"
+    ],
+    "type": "string"
+  },
+  {
+    "maxItems": 2,
+    "minItems": 2,
+    "prefixItems": [
+      {
+        "type": "integer"
+      },
+      {
+        "type": "integer"
+      }
+    ],
+    "type": "array"
+  },
+  {
+    "pattern": "^(signed |unsigned )?word\\[[1-9][0-9]*\\]$",
+    "type": "string"
+  }
+]

changedInput schema / $defs / ContractSpec / properties / outputs / description

Previous value: -"Output variables: \"bool\", [low, high], or \"real\""New value: +"Output variables: \"bool\", [low, high], \"real\", or \"word[n]\" (\"signed word[n]\")"

First observedv0.3.1Oct 27, 2026

TDQS

B3/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuinely non-obvious semantics beyond that: the result is an abstraction refined by the original contract, which is a real behavioral claim. It still omits whether a new ContractSpec is returned versus the input mutated, and what the 'name' parameter does to the result.

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 short sentences with no filler, and the core action is front-loaded. The embedded formal notation ((b & A, b -> G)) is dense but does real work by pinning down the semantics.

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 no output schema, the description does at least indicate the return is a contract ('the result is an abstraction of the contract'). However, for a 3-parameter tool with a nested ContractSpec operand and an unexplained 'name' parameter, more is needed — e.g. what the returned spec looks like and how 'name' affects it.

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

Parameters2/5

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

Top-level schema coverage is 0% — neither 'formula', 'contract', nor 'name' has a description. The text partially compensates by tying 'b' to the formula and naming the contract operand, but the 'name' parameter is never mentioned at all, leaving one of three parameters undocumented in both schema and description.

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 names a specific verb and resource ('Add an assumption b to the contract') and even sketches the resulting semantic shape ((b & A, b -> G)). It is clearly distinct from guarantee-adding or algebra siblings like ensure/compose, though it never names an alternative. The notation is jargon-heavy but the intent is recoverable.

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

Usage Guidelines2/5

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

There is no statement of when to use this versus alternatives such as ensure (the apparent guarantee-side counterpart), conjoin, or repair. The agent must infer the use case (strengthening the environment assumption, e.g. to make a contract realizable) entirely from the name and formula sketch.

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