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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description's one genuine addition is the cost metadata (10 credits, Tier 1), which matters for agent budgeting. It still says nothing about how seeding works, whether the spread is deterministic, or whether a question is required to get a meaningful reading.

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?

Front-loaded and free of filler: the spread definition comes first, with group and cost as compact bracketed metadata. It is efficient, though its brevity edges toward under-specification rather than disciplined concision.

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 5-parameter divination tool, the definition is incomplete: no explanation of the question/seed/allowReversed semantics, no usage context, and no note that all parameters are optional and the spread can be drawn cold. The output schema does relieve it of explaining return values, but the remaining gaps are substantial.

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 40% — 'fields' and 'precision' are documented in the schema but 'seed', 'question' and 'allowReversed' are bare. The description contributes zero parameter meaning, so it does nothing to compensate for the undocumented half. An agent cannot tell from either source what 'question' does or how 'seed' affects reproducibility.

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 fragment '4-card career spread' identifies the resource and the deck variant via the [Group: Tarot: Marseille] tag, and adds the card count beyond the title 'Marseille: Career'. However there is no verb ('draw', 'deal') and no explicit differentiation from astroway_tarot_rider_waite_draw_career or the other Marseille spreads (love, spiritual, decision) — the agent must infer the distinction 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?

No when-to-use guidance at all: nothing says when to pick a career spread over draw_three_card or draw_celtic_cross, when Marseille is preferred over Rider-Waite, or whether the caller should supply a question. The only selection signal is the tool name.

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