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

Annotations already declare read-only, idempotent, harmless behavior. The description adds useful behavioral context by revealing that results include page addresses and that each deck has unique card meanings, which goes beyond the structured annotations.

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 two short sentences, front-loaded with the core purpose, and adds only essential details. No wasted words or redundancy.

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 listing tool with one optional parameter and no output schema, the description provides sufficient context: it explains the content (decks) and mentions page addresses and unique card meanings. It could mention response format or filtering, but given the simplicity, it is adequately complete.

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 schema fully describes the only parameter 'locale' with an enum and default. The tool description does not mention this parameter, but since schema coverage is 100%, the description does not need to add more. It neither repeats nor adds extra value, so a baseline of 3 is appropriate.

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 lists Arcanika decks (Tarot and oracles) with page addresses, and notes that each deck has its own card meanings. This specific verb+resource combination distinguishes it from sibling tools like get_card_meaning or list_spreads, making the purpose unambiguous.

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 the general context (listing decks with page addresses) but does not explicitly state when to use this tool versus others, nor any exclusions or prerequisites. The distinction is implicit from the name and siblings, but no direct guidance is provided.

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