custom_queryExecute custom Apicalypse queries to retrieve specific video game data from IGDB endpoints like games, companies, or platforms.
Run a custom Apicalypse query against any IGDB API endpoint
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | The Apicalypse query string | |
| endpoint | Yes | The API endpoint to query (e.g., 'games', 'companies', 'platforms', 'people', 'characters') |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. While it mentions 'Apicalypse query' (implying a specific query language/syntax), it doesn't address authentication requirements, rate limits, error handling, response format, or whether this is a read-only vs. mutation operation. The description provides minimal behavioral context beyond the basic action.
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, efficient sentence that communicates the core functionality without any wasted words. It's appropriately sized for a tool with two parameters and good schema documentation, and the information is front-loaded with the essential action and target.
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 an output schema (which handles return values), 100% parameter schema coverage, and no complex nested objects, the description is minimally adequate. However, for a flexible query tool with no annotations and specialized sibling tools, it should provide more guidance about when to use it versus the alternatives and more context about the Apicalypse query language.
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?
With 100% schema description coverage, the input schema already fully documents both parameters (endpoint and query). The description doesn't add meaningful semantic context beyond what's in the schema descriptions, such as explaining Apicalypse syntax in more detail or providing endpoint usage patterns. The baseline of 3 is appropriate when the schema does the heavy lifting.
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 clearly states the action ('Run a custom Apicalypse query') and target resource ('against any IGDB API endpoint'), providing a specific verb+resource combination. However, it doesn't explicitly differentiate from sibling tools like 'search_games' or explain when to use this more flexible tool versus the specialized ones.
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 provides no guidance about when to use this tool versus the sibling tools (get_game_details, get_most_anticipated_games, search_games). There's no mention of prerequisites, alternatives, or specific scenarios where this custom query approach is preferable to the more specialized tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.