get_card_factsEverything the public catalog holds on one card: issuer, annual fee, network, foreign transaction fee, rewards currency, and the names of its statement credits, lounge networks and protections. Card name is matched loosely. Card facts only — no earning rates, welcome-offer amounts, transfer ratios, or bonus sizes.
| Name | Required | Description | Default |
|---|---|---|---|
| card_name | Yes | Card name, e.g. 'Amex Platinum' or 'Venture X'. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does disclose important behavior: 'Card name is matched loosely,' the exact field categories, and what is deliberately omitted. It does not describe no-match or ambiguous-match behavior, but for a simple lookup this is solid disclosure.
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 compact and front-loaded: one sentence scopes and lists the fields, and a short second sentence states exclusions. Every clause adds useful information with no filler.
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 one-parameter lookup with no output schema, the description is nearly complete: it lists the returned facts, explains matching behavior, and clarifies limitations. A small gap is that it does not say what happens when no card matches or when a loose match is ambiguous.
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 baseline is 3. The description adds meaning beyond the schema by explicitly stating that card_name is matched loosely, telling the agent that exact naming is not required.
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 identifies a precise resource (one card's catalog record) and enumerates the exact facts returned, including issuer, annual fee, network, and foreign transaction fee. It also lists exclusions, clearly distinguishing it from sibling tools like estimate_point_value and find_transfer_routes.
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 provides clear context for when to use the tool: when a single card's catalog facts are needed. It explicitly states exclusions (no earning rates, welcome-offer amounts, transfer ratios, or bonus sizes), but it does not name the specific sibling tools to use instead.
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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Each tool targets a distinct operation: search for cards, get one card's full facts, compare multiple cards, estimate point values, and find transfer routes. There is no meaningful overlap or ambiguity between them.
All tool names follow a consistent verb_noun snake_case pattern: search_card_catalog, get_card_facts, compare_card_facts, estimate_point_value, find_transfer_routes. The naming is uniform and predictable.
Five tools is a well-scoped size for a read-only catalog server with related loyalty utilities. Each tool earns its place, and the count is neither too thin nor overwhelming.
For a catalog of credit card facts plus loyalty point and transfer route lookups, the surface is complete: discover cards, inspect details, compare cards, estimate values, and trace transfer routes. The exclusions are explicitly declared and do not represent dead ends within the stated scope.