card_random

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

No annotations are provided, so the description carries the full burden of disclosure. It does usefully state the output ('Returns the full card object') and confirms the q filter reuses card_search syntax, which is meaningful behavioral context. However, it doesn't disclose that results are non-deterministic across calls, potential error behavior on invalid queries, or any Scryfall request implications.

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 with the core purpose front-loaded and the q filter explained second. No filler or redundancy — every sentence contributes meaning.

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 simple single-optional-param random fetcher, the description covers what's needed: the return shape is stated, the query construction approach is referenced, and the schema documents the sole parameter. Minor gaps like query-with-no-matches behavior and non-determinism are not addressed, but these are secondary for this tool's simplicity.

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% and the schema already documents q as an optional filter restricting the random pool. The description adds genuine value by stating that q follows the exact same Scryfall query syntax as card_search, giving the agent a concrete reference for constructing complex filters.

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 identifies the resource ('a random Magic card') and the core verb ('returns'), and the word 'random' immediately differentiates it from siblings like card_search, card_named, and card_fuzzy. It's not a tautology. It could be slightly stronger by explicitly contrasting with deterministic lookup tools, but the 'random' framing carries enough distinction.

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 intent is implied rather than stated — the tool's random nature signals when an agent would reach for it. The explicit reference to card_search's query syntax is a useful pointer for constructing the q filter, but there's no explicit when/when-not guidance (e.g., 'use card_named for a specific card, use this for arbitrary selection').

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