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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered. The description contributes genuine extra context: a cost of 10 credits (Tier 1) and the POST endpoint, which the annotations do not express. It stops short of explaining how the date seed affects output (determinism, whether omitting date means today), which is the behavior an agent would most want to know.

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: the core purpose is in the first clause, and the metadata lines (group, endpoint, cost) are compact and each carries real information. No filler or repetition, though the brevity edges toward under-specification rather than elegance.

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 not be described, and annotations cover the safety profile. What remains missing for a 4-optional-param tool is defaulting behavior (is date optional because it defaults to today?) and any routing guidance among the many tarot daily/draw siblings. Adequate but with clear gaps.

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 75%, so most parameters are already documented in the schema. The phrase 'based on date seed' hints that the date parameter determines the card deterministically, but the description says nothing about the art, fields, or precision parameters and does not clarify date defaults. Baseline 3 is appropriate given the schema does the heavy lifting.

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 (the Marseille daily card) and adds the mechanism (date seed), which lets an agent separate it from astroway_tarot_rider_waite_daily and astroway_tarot_lenormand_daily by deck. It is weaker on verb phrasing — there is no explicit 'returns/gets' action — and the core sentence closely mirrors the title 'Marseille: Daily Card', so it sits just below a fully self-contained purpose statement.

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 or when-not-to-use guidance. Nothing tells the agent how this differs in practice from astroway_tarot_marseille_draw_single or astroway_tarot_marseille_birth_card, nor whether it should be called once per day. 'Daily' implies a cadence, but that inference is left entirely to the caller.

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