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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds genuinely new operational context — the endpoint and a 10-credit Tier 1 cost — which is useful for budget-aware planning, but it says nothing about caching, latency, or whether the result is static reference data.

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 front-loaded sentence states the payload, followed by three bracketed metadata lines (group, endpoint, cost) that each carry distinct, non-redundant information. Nothing is padded or repeated.

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 needn't be explained, and the tool takes no required parameters. What remains missing is minor: no hint that it is a parameterless static reference call or how its output relates to a tableau draw, but nothing needed to invoke it correctly is absent.

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 100% and both parameters (fields, precision) are fully documented in the schema, including examples and semantics, so the baseline is 3. The description adds nothing about the compact-mode parameters, which is acceptable when the schema already carries them.

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 36 fixed houses') and its domain role ('for Grand Tableau interpretation'), so an agent knows exactly what comes back. It does not, however, distinguish itself from siblings like astroway_tarot_lenormand_draw_grand_tableau or astroway_lnd_celtic_cross_lenormand, leaving the agent to infer the boundary itself.

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?

Mentioning 'Grand Tableau interpretation' implies the usage context, but there is no explicit when-to-use, no prerequisite, and no named alternative. An agent can guess this is a static reference lookup that complements a tableau draw, but the routing decision is left to inference.

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