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

Annotations already declare this a safe, read-only, idempotent operation, so the safety profile is covered. The description adds genuinely useful non-annotation context in the cost/tier line ('10 credits (Tier 1)'), but says nothing about the shape or size of the returned spread list, which is the main behavioral unknown.

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?

One sentence plus two minimal metadata lines, with the resource stated first. It is compact and front-loaded; only slight credit is withheld because the metadata lines consume space without aiding tool selection.

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 read-only listing tool with an output schema and full annotation coverage, the essential purpose is conveyed. What is missing is any routing signal relative to astroway_tarot_marseille_spreads_slug and the other Marseille spread/draw tools in the sibling 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?

Schema coverage is 100% and both parameters (fields, precision) are fully documented in the schema itself as generic compact-mode controls. The description adds no parameter meaning beyond that, so the baseline 3 for a well-documented schema 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 names a specific resource (Marseille spreads) and verb (list), and even calls out a notable member (Jodorowsky cross). It does not, however, distinguish this tool from the obvious sibling astroway_tarot_marseille_spreads_slug, so an agent must infer the difference from the name alone.

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, no mention of the slug-based alternative, and no stated preconditions. The only context is the '[Group: Tarot: Marseille]' tag, which is taxonomy rather than usage direction.

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