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prices

Read-onlyIdempotent

The price table every figure is computed from, in US dollars per million tokens, with the date it was last verified. Includes any overrides from the user's config.

Instructions

The price table every figure is computed from, in US dollars per million tokens, with the date it was last verified. Includes any overrides from the user's config.

Input Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Output Schema

TableJSON Schema

Name	Required	Description
`unit`	Yes	always usd_per_million_tokens
`models`	Yes
`verified`	Yes	the date the built-in table was last checked against the vendors' price pages
`scan_error`	No	why the most recent scan attempt failed, in which case the figures are from the last successful scan
`age_seconds`	Yes	seconds since that scan; the server rescans when a tool is called more than 60 seconds after the last attempt, or on refresh
`ingested_at`	Yes	RFC 3339 time of the last successful transcript scan; empty if none has succeeded yet

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv1.2.0Sep 13, 2026

addedOutput schema / properties / models / items / properties / fast

Added value: +{
+  "additionalProperties": false,
+  "description": "the rate this model bills under fast mode, absent when it has none",
+  "properties": {
+    "cache_read": {
+      "type": "number"
+    },
+    "cache_write_1h": {
+      "type": "number"
+    },
+    "cache_write_5m": {
+      "type": "number"
+    },
+    "input": {
+      "type": "number"
+    },
+    "output": {
+      "type": "number"
+    }
+  },
+  "required": [
+    "input",
+    "cache_read",
+    "cache_write_5m",
+    "cache_write_1h",
+    "output"
+  ],
+  "type": [
+    "null",
+    "object"
+  ]
+}

addedOutput schema / properties / models / items / properties / long

Added value: +{
+  "additionalProperties": false,
+  "description": "the rate this model bills once the prompt passes long_context_from tokens, absent when it has none",
+  "properties": {
+    "cache_read": {
+      "type": "number"
+    },
+    "cache_write_1h": {
+      "type": "number"
+    },
+    "cache_write_5m": {
+      "type": "number"
+    },
+    "input": {
+      "type": "number"
+    },
+    "output": {
+      "type": "number"
+    }
+  },
+  "required": [
+    "input",
+    "cache_read",
+    "cache_write_5m",
+    "cache_write_1h",
+    "output"
+  ],
+  "type": [
+    "null",
+    "object"
+  ]
+}

addedOutput schema / properties / models / items / properties / long_context_from

Added value: +{
+  "description": "prompt size in tokens above which long applies",
+  "type": "integer"
+}

First observedv0.1.0Sep 12, 2026

TDQS

B3.2/5.0

Behavior3/5

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

Annotations declare readOnlyHint, idempotentHint, and openWorldHint=false, covering safety and side-effect profile. The description adds useful context: the data is in USD per million tokens, includes a last-verified date, and incorporates user config overrides. However, it does not describe pagination, caching, or authentication needs.

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?

The description is a single efficient sentence, front-loading the resource and units. It is appropriately sized for a zero-parameter tool, though it could be slightly clearer with an explicit verb.

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?

Given a zero-parameter tool with annotations and an output schema, the description covers the essential context (units, verification date, overrides). It is nearly complete, missing only minor usage guidance, but that is not required for correctness.

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

Parameters4/5

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

With zero parameters and 100% schema coverage (empty schema), the baseline is 4. The description appropriately does not invent parameter details, correctly implying a parameterless read.

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

Purpose3/5

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

Describes a resource ('the price table') and its content (USD per million tokens, verification date, config overrides), but uses no verb and is titled 'prices' with no clear action. An agent can infer it returns pricing data, but it isn't explicitly stated what operation occurs or how it differs from siblings like 'refresh' or 'report'.

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 guidance on when to use this tool versus alternatives. The description does not mention siblings such as 'refresh' (which might update this table) or explain the conditions under which an agent should call 'prices'.

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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