most_valuableUse this when the user asks for the most expensive or most valuable cards in one game right now. Returns up to 25 singles ranked by today's raw market price (USD) with set and printing. Raw prices only, not graded values.
| Name | Required | Description | Default |
|---|---|---|---|
| game | No | Card game, one of: pokemon, one-piece, lorcana, riftbound, yugioh, gundam. | pokemon |
| limit | No | 1 to 25. |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Input schema / properties / game / descriptionAdded value: +"Card game, one of: pokemon, one-piece, lorcana, riftbound, yugioh, gundam."Input schema / properties / game / enumAdded value: +[
+ "pokemon",
+ "one-piece",
+ "lorcana",
+ "riftbound",
+ "yugioh",
+ "gundam"
+]Input schema / properties / limit / descriptionAdded value: +"1 to 25."Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the read-only annotations, the description discloses result composition ('up to 25 singles'), ranking method ('today's raw market price (USD)'), included fields ('set and printing'), and an important boundary ('Raw prices only, not graded values'). These details materially help an agent understand what the tool returns and what it does not cover.
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?
Three tight sentences, front-loaded with the usage trigger, followed by return details and an exclusion. No sentence is wasted.
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?
For a two-parameter, read-only list tool with an output schema, the description covers usage, ranking, included data, currency, and exclusions. An agent has enough information to invoke it correctly without needing further explanation.
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 coverage is 100%, so the schema already documents both parameters, including the game enum and the 1–25 limit range. The description reinforces 'one game' and 'up to 25' but adds no syntax or selection guidance beyond the schema.
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 resource (most expensive/most valuable cards), scope (one game), and temporal qualifier ('right now'). The phrase 'today's raw market price' distinguishes it from sibling tools like all_time_highs and price_history without ambiguity.
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?
It gives an explicit usage trigger: 'Use this when the user asks for the most expensive or most valuable cards in one game right now.' It also implicitly excludes historical comparisons and graded values, though it does not explicitly name alternatives such as all_time_highs or card_price.
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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