List all 11 tracked dealers ranked by price for a coin, best first, with in-stock status (✅/❌) for each. Accepts a coin slug or name (ex: krugerrand-1oz-or, souverain, napoleon). Prices refreshed daily directly from each dealer's website.
| Name | Required | Description | Default |
|---|---|---|---|
| coin | Yes | Coin slug or name. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the behavioral disclosure burden. It states that prices are refreshed daily directly from dealer websites, indicating cached data rather than live queries, and explicitly includes in-stock status. It does not mention error handling or rate limits, but for a read-only listing tool the key behavioral traits are well covered.
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 sentences, each with a clear purpose: what is returned, what input is accepted, and how the data is sourced. No filler or repetition. The main function is front-loaded in the first sentence.
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?
The tool has only one required parameter and no output schema, so the description must explain the return shape. It does: a ranked list of all 11 dealers with in-stock status. It also covers input format and data freshness. Minor omissions like currency or sort tie-breakers do not prevent correct usage for a straightforward price comparison tool.
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%, so the baseline is 3. The description adds value by clarifying that 'coin' accepts either a slug or name and gives concrete examples (krugerrand-1oz-or, souverain, napoleon), which reduces ambiguity about acceptable input formats beyond the schema's generic 'Coin slug or name.'
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 provides a specific verb ('List') and resource ('all 11 tracked dealers ranked by price for a coin'), with concrete output details like in-stock status. This clearly distinguishes compare_prices from siblings such as get_best_price (which would not list all dealers) and list_dealers (which would not be coin-specific).
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?
Usage is implied through the description: use this when you need dealer price comparisons for a specific coin. It accepts a coin slug or name with examples. However, there is no explicit guidance about when to choose this over alternatives like get_best_price or compare_coins, so the agent must infer the intended use case.
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.
compare_prices and get_best_price are nearly identical: both accept a coin slug or name and return the same ranked list of all 11 dealer prices with in-stock status. The other tools are distinct, but this clear functional overlap creates real selection ambiguity.
All six tools follow a consistent lowercase snake_case verb_noun pattern: compare_coins, compare_prices, get_best_price, get_coin_specs, list_dealers, search_coins. Verbs are action-oriented and predictable, making the tool surface easy to navigate.
Six tools is a reasonable size for a bullion coin information and price comparison server. The count is not excessive, though one tool is largely redundant with another, so the set is slightly less tight than it could be.
The server covers the apparent domain well: searching the catalog, retrieving full coin specs, comparing dealer prices, doing side-by-side coin comparisons, and listing dealers. Minor gaps like a dedicated spot price tool or dealer detail view exist, but core informational needs are covered.
