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

Annotations already declare readOnly, non-destructive and idempotent, so safety is covered. The description's one genuinely additive fact is the cost (10 credits, Tier 1) plus the endpoint, but 'seeded' merely restates the idempotentHint rather than explaining determinism, randomness fallback, or output shape.

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 prose is a single front-loaded sentence, with the remaining lines being compact structured metadata (group, endpoint, cost) rather than filler. Nothing is redundant, though the metadata block is more operational than descriptive.

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 explained, and there are zero required parameters, making this a low-complexity call. Combined with annotations covering the safety profile, the definition supplies enough for an agent to invoke it, though the seed semantics remain thin.

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 67%: `fields` and `precision` are well documented in the schema, while `seed` has none. The word 'Seeded' in the description partially compensates by hinting that `seed` drives determinism, but it never states the accepted types or the effect of omitting it. Baseline 3 given the moderate coverage.

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?

"Seeded 3-coin method" signals an I Ching coin-toss divination, but it names neither the verb (cast/generate) nor the resource (hexagram) explicitly and never distinguishes itself from siblings like astroway_iching_with_changing_lines or astroway_iching_by_question. The name carries most of the meaning; the description adds only the 'seeded' qualifier.

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 guidance at all — nothing says when to pick this over astroway_iching_daily, by_question, or with_changing_lines, nor what happens when no seed is supplied. The cost/group metadata is not usage guidance.

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