Marseille: Year Card

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered by structured data. The description's only genuine addition is the cost line (10 credits, Tier 1) and the concrete HTTP endpoint, which help an agent weigh whether to call, but nothing is said about how the Greer computation behaves or what it depends on.

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?

Four short lines with the operative phrase front-loaded and no filler. The bracketed metadata block is compact and consistent, though it consumes most of the definition's real estate relative to the single sentence of actual purpose.

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 annotations cover safety. But for a niche method (Greer year card) the description leaves the core concept undefined and the two required parameters semantically ambiguous, which is a real gap for an agent that must decide between this and the dozens of adjacent tarot tools.

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 33%: `art` is documented in the schema, while `date` and `year` carry only a regex and a numeric range with no semantic description. The description's "[Required: date, year]" merely echoes the required array and never clarifies that `date` is a birth date and `year` is the target year being profiled — exactly the ambiguity that needed resolving.

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?

Names a specific artifact ("Year card") and credits a method ("Greer"), which is more informative than a bare title restatement, but it never says what is being calculated or how the result differs from the sibling astroway_tarot_marseille_birth_card. There is no verb (compute/derive/look up), so the agent must infer the operation from the name and endpoint.

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 contains no when-to-use guidance, no exclusions, and no reference to any of the many nearby alternatives (birth_card, daily, rider_waite_year_card). The only constraint given is "[Required: date, year]", which is already declared in the input schema's required array, so it adds no routing guidance.

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