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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real context beyond that: lodge widths are unequal and precession-dependent, results carry an attribution line and permalink, and no interpretive verdict is returned.

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 core computation and output enumerations are front-loaded in the first sentence, with caveats and return notes following. Every sentence carries information, though the standalone note about unequal lodges reads as slightly detached.

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?

With no output schema, the description compensates by naming the returned fields (longitude, lodge, du, palace, dignities, page locators, attribution, permalink). For a deterministic read-only computation with 3 fully documented parameters, nothing essential is missing.

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%, with formats and examples already documented for all three parameters. The description only restates that date, time and place drive the computation, adding no format or constraint detail beyond the schema.

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?

A specific verb ('Computes') on a precisely named resource ('Chinese Seven Governors and Four Remainders chart'), followed by an enumeration of the exact outputs produced. This clearly separates it from siblings like compute_birth_chart or compute_four_pillars, which cover different systems.

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 implied by the required 'date'/'time'/'place' trio, and the 'Facts only: no reading or verdict' line sets expectation about scope. However, it never states when to choose this over compute_birth_chart or compute_four_pillars, leaving sibling routing to inference.

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