Hexagram Compatibility

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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds real value beyond that: it discloses that the 0-100 score's formula is stated in the response and is an API convention rather than a classical measure, plus the cost tier (10 credits) and the POST endpoint — context an agent would not get from structured fields.

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?

A single dense but well-ordered sentence front-loads the verb and then enumerates outputs in a scannable list, followed by a compact metadata block for group, endpoint, required params and cost. No filler sentences and nothing 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?

The tool is simple (two integer inputs, output schema present, annotations covering safety), and the description covers the interpretive caveat about the score plus cost and transport details. The only omission is any routing guidance against the many sibling I Ching tools, which is minor given the output schema handles return values.

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 100% and both parameters are documented as King Wen numbers bounded 1-64. The description only restates that hexagramA and hexagramB are required, adding no meaning beyond the schema, so the baseline of 3 applies.

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?

States a specific verb and resource ('Compares two hexagrams') and enumerates the concrete outputs — matching/differing lines, named relations, five-phase relations, and a 0-100 score — which effectively separates it from the reading/daily/throw_coins siblings. It stops short of naming any sibling as an alternative, so it is clear but not explicitly differentiated.

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?

Usage is only implied: an agent can infer this is the tool for pairwise hexagram comparison because of the two required hexagram parameters. There is no statement of when to prefer this over astroway_iching_reading or astroway_iching_trigram_analysis, and no exclusions or prerequisites are given.

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