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

Annotations already declare read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: a 366-day range cap that hard-refuses rather than truncates, and the optional clash filter keyed to a person's animal. It stops short of noting cost/auth handling, which the separate cost line partly supplies.

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?

Two sentences, zero waste. The core behavior is front-loaded and the constraints (clash filter, range cap, refuse-not-truncate) follow immediately; nothing is repeated from the schema or annotations.

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-value explanation is unnecessary, and the description covers the main behavioral risks (range cap, refusal semantics, clash filtering). The gaps are the unaddressed includeNeutral and language parameters and the exact date format, which the schema pattern supplies.

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?

With only 25% schema description coverage across 8 parameters, the description must compensate and partly does: it clarifies activity (one per call), from/to as a walked range, and avoidClashWith as dropping animal-clash days. It says nothing about includeNeutral or language, leaving two parameters unexplained in both schema and prose.

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 precise verb+resource: walks a date range and returns almanac-endorsed days for a single activity, each annotated with the deciding officer. This clearly separates it from the singular sibling astroway_chinese_tong_shu, which covers one date rather than a selection sweep.

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 use case is clearly articulated (pick auspicious days for one named activity, optionally excluding days that clash a person's animal), and the 366-day cap sets a boundary on valid input. It does not, however, name an alternative (e.g. the single-date tong_shu tool or the vedic_muhurat family) or state when not to use it.

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