card_fuzzy

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

With no annotations, the description carries the full burden. It discloses the supported input variations, the return shape ('full card object'), and the failure behavior ('no close match surfaces as an error carrying Scryfall's details'). This is strong behavioral disclosure for a lookup tool, though it omits details like rate limits or any selection/preference when multiple matches are equally close.

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 earning its place: the core function, the behavioral details, and the usage condition. The most important identifier, 'Fuzzy-name lookup', is front-loaded, and there is no filler or repetition.

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 single-parameter lookup tool with no output schema, the description covers all essentials: what it does, what input variations it accepts, what the return looks like, how errors surface, and when to reach for it. Nothing an agent needs to invoke it correctly is missing.

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% and the schema already labels 'name' as an approximate card name. The description adds value by elaborating what 'approximate' means: typos, partial names, and alternate spellings. This enriches the parameter beyond the bare schema text.

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 opens with the specific verb 'Fuzzy-name lookup' and a clear resource ('a Magic card'), then details what 'fuzzy' means (typos, partial names, alternate spellings). This distinguishes it from card_named, card_search, and card_collection without needing to open the schema.

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 explicitly states when to use the tool ('Use when the caller's spelling may be wrong or incomplete'), giving a clear context. However, it does not name the alternative (e.g., card_named for exact names) or state an exclusion condition, so it stops short of a full when/when-not directive.

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