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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds useful billing context ([Cost: 10 credits (Tier 1)]) and the endpoint, but discloses nothing else about behavior beyond what the annotations provide.

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?

Very short and front-loaded, with metadata tags clearly separated. No wasted prose, though the brevity reflects under-specification rather than deliberate economy.

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?

An output schema exists so return values need no explanation, and direction is covered by annotations, but for a listing tool inside a dense Marseille tool family the description does nothing to help an agent choose it or understand how it differs from the full-deck 'cards' endpoint.

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 both 'fields' and 'precision' are fully documented in the schema, so the baseline is 3. The description contributes no additional meaning about how these parameters affect this specific listing.

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 '22 Major Arcana of Marseille deck' essentially restates the title 'Marseille: 22 Majors' with no verb indicating what operation occurs (list? draw? describe?). It names the resource but leaves the action ambiguous and does nothing to distinguish it from siblings like astroway_tarot_marseille_cards.

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?

There is no when-to-use guidance whatsoever, no mention of the related Marseille card/spread tools, and no condition under which an agent should prefer this over astroway_tarot_marseille_cards or astroway_tarot_marseille_spreads.

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