commerce_listingsGuild Wars 2 Trading Post order-book depth for numeric item IDs; returns every standing buy and sell listing tier with its copper unit price, listing count, and quantity, so you can see how deep the book is at each price level.
| Name | Required | Description | Default |
|---|---|---|---|
| ids | No | Comma-separated numeric item IDs, e.g. "19976". |
| Name | Required | Description | Default |
|---|---|---|---|
| count | No | Number of items returned. | |
| items | No | Trading post listings |
Changes observed during successful MCP inspections.
Input schema / properties / ids / descriptionAdded value: +"Comma-separated numeric item IDs, e.g. \"19976\"."Output schema / properties / count / typePrevious value: -"integer"New value: +"number"Output schema / properties / items / items / propertiesRemoved value: -{
- "buys": {
- "items": {
- "properties": {
- "listings": {
- "description": "Number of buy listings",
- "type": "number"
- },
- "quantity": {
- "description": "Total quantity",
- "type": "number"
- },
- "unit_price": {
- "description": "Unit price",
- "type": "number"
- }
- },
- "type": "object"
- },
- "type": "array"
- },
- "id": {
- "description": "Item ID",
- "type": "number"
- },
- "sells": {
- "items": {
- "properties": {
- "listings": {
- "description": "Number of sell listings",
- "type": "number"
- },
- "quantity": {
- "description": "Total quantity",
- "type": "number"
- },
- "unit_price": {
- "description": "Unit price",
- "type": "number"
- }
- },
- "type": "object"
- },
- "type": "array"
- }
-}Output schema / properties / items / items / typePrevious value: -"object"New value: +"number"Output schema / requiredRemoved value: -[
- "items",
- "count"
-]Input schema / examplesAdded value: +[
+ {
+ "ids": "19684,24291"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "count": {
+ "description": "Number of items returned.",
+ "type": "integer"
+ },
+ "items": {
+ "description": "Trading post listings",
+ "items": {
+ "properties": {
+ "buys": {
+ "items": {
+ "properties": {
+ "listings": {
+ "description": "Number of buy listings",
+ "type": "number"
+ },
+ "quantity": {
+ "description": "Total quantity",
+ "type": "number"
+ },
+ "unit_price": {
+ "description": "Unit price",
+ "type": "number"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "id": {
+ "description": "Item ID",
+ "type": "number"
+ },
+ "sells": {
+ "items": {
+ "properties": {
+ "listings": {
+ "description": "Number of sell listings",
+ "type": "number"
+ },
+ "quantity": {
+ "description": "Total quantity",
+ "type": "number"
+ },
+ "unit_price": {
+ "description": "Unit price",
+ "type": "number"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "items",
+ "count"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds behavioral context by explaining that the tool returns all depth levels and what data each tier contains, going beyond the structured annotation fields.
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?
The description is a single sentence that packs essential information about purpose and output. It is somewhat dense, but every phrase contributes value and it is easy to parse. It is not overlong, earning a solid 4.
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?
With one parameter, full schema coverage, and an output schema present, the description is largely complete. It explains the return semantics and use case. Minor gaps exist (e.g., whether the ids parameter is required), but these are addressed by the schema and annotations.
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 100%, with the 'ids' parameter fully described in the schema. The description only reiterates that the IDs are numeric, adding no significant meaning beyond the schema, so the baseline of 3 is appropriate.
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 uses a specific verb ('returns') and a specific resource ('Guild Wars 2 Trading Post order-book depth'), clearly distinguishing it from sibling tools like commerce_prices. It details what is returned (every standing buy and sell listing tier with price, count, and quantity), making the purpose unmistakable.
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?
The description clearly implies when to use the tool: when you need order-book depth for item IDs rather than just a current price. It does not explicitly compare to alternatives or state when not to use, but the context is unambiguous enough for an agent to select it appropriately.
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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