Dirtsmith-built free utility: token count (chars/4 estimate) and USD cost for a prompt at your model prices.
| Name | Required | Description | Default |
|---|---|---|---|
| text | No | ||
| calls | No | ||
| input_tokens | No | ||
| output_tokens | No | ||
| usd_per_mtok_in | No | ||
| usd_per_mtok_out | No |
| Name | Required | Description | Default |
|---|---|---|---|
| ok | No | ||
| next | No | ||
| note | No | ||
| calls | No | ||
| built_by | No | ||
| usd_total | No | ||
| house_tool | No | ||
| input_tokens | No | ||
| usd_per_call | No | ||
| output_tokens | No |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "built_by": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "calls": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "house_tool": {
+ "type": [
+ "boolean",
+ "null"
+ ]
+ },
+ "input_tokens": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "next": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "note": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "ok": {
+ "type": [
+ "boolean",
+ "null"
+ ]
+ },
+ "output_tokens": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "usd_per_call": {
+ "type": [
+ "number",
+ "null"
+ ]
+ },
+ "usd_total": {
+ "type": [
+ "number",
+ "null"
+ ]
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description adds one genuinely useful behavioral trait: the count is a 'chars/4 estimate' rather than an exact tokenizer result, warning the agent that output is approximate. It says nothing about determinism, limits, or pricing defaults.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single tight sentence, front-loaded with the core function. It is well-sized for the task, though the 'Dirtsmith-built free utility' branding adds little value for tool selection.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
An output schema exists, so return values need not be explained. However, for a 6-parameter tool with 0% schema description coverage and no required fields, the description is too thin to guide correct invocation: it omits the 'calls' parameter, the in/out token and price split, and any usage context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0% across 6 parameters, so the description must compensate, and it only partially does. It maps loosely to text ('prompt'), the token inputs ('token count'), and prices ('your model prices'), but never mentions the 'calls' multiplier or the in/out price distinction, leaving key parameters undocumented everywhere.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific function: it computes a token count and a USD cost for a prompt given model prices. That is a clear verb-plus-output statement. It does not, however, distinguish itself from potentially overlapping siblings such as price_advisor, so it stops 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.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no when-to-use guidance, no prerequisites, and no mention of alternatives among the 24 sibling tools. The agent is left to infer that this is a pre-flight estimation utility from the words 'utility' and 'estimate' alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.