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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered and the description does not need to repeat it. The description adds genuinely new operational context — group, HTTP endpoint, and a 10-credit Tier 1 cost — which matters for budgeting calls, but says nothing about page size or the size of the returned reference table.

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 payload is stated front-loaded in a single dense sentence, followed by three short tagged metadata lines (group, endpoint, cost). Nothing is padded or redundant, though the bracketed metadata block is boilerplate rather than tool-specific guidance.

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?

This is a low-complexity, zero-required-parameter static lookup tool: annotations cover the safety profile, an output schema covers return values, and the schema covers both optional params. The description supplies the content inventory plus cost and endpoint, so an agent has everything needed to call it correctly.

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%, so both `fields` and `precision` are already fully documented, making 3 the baseline. The description's enumeration of what data is present indirectly helps an agent build dotted `fields` paths, but it never names or explains the parameters or gives example paths.

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 clearly states the resource and its contents (eight trigrams with lines, image, attribute, family member, animal, body part, Shuo Gua/Earlier/Later Heaven numbers and directions, five-phase element), so an agent knows it is a static reference dump. It does not distinguish itself from the nearby astroway_iching_trigram_analysis sibling, which is the only missing differentiator.

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, no exclusions, and no pointer to alternatives such as astroway_iching_trigram_analysis or astroway_iching_lookup_number. The agent must infer that this is the bulk reference table rather than a computed reading, purely from the enumerated field list.

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