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

Annotations already cover read-only and non-destructive behavior. The description adds genuinely useful behavioral context by explaining seeded randomness, the guarantee that same seed + same day yields the same hexagram, and the contents of the returned reading. This is good disclosure beyond the structured annotations.

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 description is front-loaded with the primary action and then expands into behavior and use cases. The second sentence is somewhat long and contains minor filler, but most of its detail about deterministic seeds and interpretation categories earns its place.

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 has no required parameters and all complex parameter semantics are already in the schema. The description covers the core behavior, the determinism contract, and the response contents sufficiently for an agent to call the tool correctly without an output schema.

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 the description does not need to compensate for undocumented parameters. It re-emphasizes seed determinism and vaguely relates to the date, but adds little semantic value beyond the schema's detailed parameter descriptions.

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 action ('Receive a daily I-Ching hexagram') and specifies what the endpoint returns: judgment, image, and interpretations for love, career, and decisions. The seeded same-day determinism also helps distinguish it from the sibling trigram, lookup, and cast tools.

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?

The description gives a clear use context ('Hexagram of the Day features in oracle apps, meditation platforms, and daily wisdom tools') and implies this is the everyday deterministic reading endpoint. However, it does not explicitly say when to choose this over siblings like post_iching_daily_cast or get_iching_hexagrams_random.

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