game_screenshotCapture a PNG preview of the running game view to verify visual output, helping AI agents observe and assess the current game state during automated development and testing.
Capture a PNG preview with dimension…
| Name | Required | Description | Default |
|---|---|---|---|
| retainArtifact | No | Retain a PNG in the system temp arti… |
| Name | Required | Description | Default |
|---|---|---|---|
| ok | Yes | ||
| data | No | ||
| meta | Yes | ||
| error | No |
Changes observed during successful MCP inspections.
v1.1.5v1.1.4v1.1.2Input schema / $schemaAdded value: +"https://json-schema.org/draft/2020-12/schema"Input schema / additionalPropertiesAdded value: +falseInput schema / properties / retainArtifact / descriptionPrevious value: -"Retain a PNG in the system temp artifact directory. Default: false"New value: +"Retain a PNG in the system temp arti…"Output schema / (root)Previous value: -nullNew value: +{
+ "additionalProperties": false,
+ "oneOf": [
+ {
+ "not": {
+ "required": [
+ "error"
+ ]
+ },
+ "properties": {
+ "ok": {
+ "const": true
+ }
+ },
+ "required": [
+ "data"
+ ]
+ },
+ {
+ "not": {
+ "required": [
+ "data"
+ ]
+ },
+ "properties": {
+ "ok": {
+ "const": false
+ }
+ },
+ "required": [
+ "error"
+ ]
+ }
+ ],
+ "properties": {
+ "data": {},
+ "error": {
+ "type": "object"
+ },
+ "meta": {
+ "type": "object"
+ },
+ "ok": {
+ "type": "boolean"
+ }
+ },
+ "required": [
+ "ok",
+ "meta"
+ ],
+ "type": "object"
+}v1.0.2Input schema / properties / retainArtifactAdded value: +{
+ "description": "Retain a PNG in the system temp artifact directory. Default: false",
+ "type": "boolean"
+}v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true (safe read), idempotentHint=true, and destructiveHint=false. The description adds minimal behavioral context beyond 'Capture a PNG preview', not elaborating on side effects or return details. The annotations carry the burden.
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 extremely short but truncated mid-sentence ('with dimension…'), making it incomplete. While conciseness is valued, this is under-specification rather than efficient writing.
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?
Given the tool has one optional parameter, an output schema (not shown), and simple functionality, a brief description could be adequate. However, the truncation and lack of parameter explanation leave it incomplete.
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% for the single parameter 'retainArtifact', but the description does not mention this parameter at all. It adds no extra meaning beyond what the schema already provides. Baseline 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 begins with 'Capture a PNG preview' which clearly indicates the tool's action (capture) and output format (PNG), and it is distinct from sibling tools like game_click. However, the description is truncated with 'with dimension…', which slightly reduces clarity.
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?
No guidance is provided on when to use this tool versus alternatives such as game_get_ui (which also captures visual state). The description does not mention use cases, prerequisites, or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.