Marseille: Celtic Cross

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the endpoint and cost (10 credits, Tier 1), which is useful behavioral context, but it does not describe the return structure or any other behavioral traits. With annotations doing the heavy lifting, this is a moderate addition.

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 short and front-loaded with the core purpose. The bracketed metadata (group, endpoint, cost) is efficient and useful for an agent. It could be slightly more informative, but there is no wasted text.

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?

Given that an output schema exists, return values need not be explained. However, the description is incomplete for a tool with four parameters at 25% schema coverage: it omits parameter semantics and does not clarify how the spread is adapted or what the pip-style reading entails. It covers purpose and cost but leaves gaps for correct invocation.

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 only 25% (one of four parameters has a description), so the description should compensate by explaining parameters like seed, question, and allowReversed. Instead, it provides no parameter information at all, leaving most inputs undocumented.

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 the specific spread (10-card Celtic Cross) and the deck style (Marseille pip-style), which distinguishes it from the Rider-Waite Celtic Cross sibling. However, it does not explicitly contrast itself with other Marseille draw tools, leaving some ambiguity about when to pick this spread over others.

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 only states what the tool does; it gives no guidance on when to use this tool versus alternatives (e.g., other Marseille spreads or the Rider-Waite Celtic Cross). No exclusions or context-dependent selection advice is provided.

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