lookup_card

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the transparency burden. It discloses matching behavior (exact then partial), data sources (LorcanaJSON and duels.ink), set selection logic (most recent unless set_name is specified), and return contents (stats, abilities, legality, image URL). It does not mention error handling or rate limits, but for a read-only lookup this is fairly transparent.

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 concise and well-structured: a clear opener stating purpose and return value, two sentences covering matching and data sources, and a compact Args section. Every sentence 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?

Given that an output schema exists, the description does not need to enumerate return fields in detail. It covers purpose, parameters, data sources, matching behavior, and edge cases like multiple printings. This is complete for a lookup tool with a small parameter set.

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?

The input schema only lists parameter names and a default, with 0% schema description coverage. The description fully compensates through an Args section: it explains that 'name' accepts exact or partial matches, provides examples, and clarifies that 'set_name' is optional and narrows the search. This adds essential meaning 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 clearly states the tool's function: 'Look up a Lorcana card by name and return its full stats, abilities, and legality.' It specifies the resource (Lorcana cards), the action (look up by name), and key details like exact/partial matching and data sources, distinguishing it from broader search or filtering tools.

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 gives clear usage context: provide a card name, optionally a set name to disambiguate. It explains fallback behavior and most-recent-printing behavior without explicitly naming alternatives. This is clear context with no exclusions, though it could have referenced sibling tools for stronger differentiation.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.