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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds useful cost/group metadata (10 credits, Tier 1, BaZi group), but says nothing about output volume, whether language affects the pillar labels, or how the decade window is bounded.

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 sentence is front-loaded and waste-free; the bracketed group/cost tags are compact and machine-scannable. Slightly more verbose than a single clean sentence, but nothing is extraneous.

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 values needn't be explained, and annotations handle safety. However, for a tool with three comparably named BaZi siblings and a required year parameter, the description is thin on routing and on what the decade output represents, leaving an agent to infer selection.

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 50%: 'fields' and 'precision' are well documented in the schema, while 'startYear' and 'language' are undocumented. The description's 'from a given starting year' loosely maps to startYear but adds no format or edge-case detail (e.g., whether the 10 pillars begin at that year inclusive). Baseline 3 fits given the schema carries the parameter detail.

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 resource and cardinality: '10 consecutive year pillars from a given starting year.' An agent can distinguish it from the singular astroway_bazi_year_pillar by the '10 consecutive'/decade framing. It stops short of naming the sibling alternative explicitly, so it's clear but not fully 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?

There is no when-to-use guidance and no routing to alternatives among the many BaZi siblings (year_pillar, yearly, luck_pillars, monthly). The '10 consecutive' scope implies a range flavor, but nothing tells the agent when this is preferred over the single-year or yearly tools.

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