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

Annotations already declare read-only, idempotent, non-destructive, so the safety bar is covered. The description adds genuinely useful context beyond that: the returned content (progressed planets, angles, aspects to natal) and the cost tier (50 credits, Tier 3), which matters for an agent managing quota.

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 front-loaded sentences with zero filler: verb first, output second. Group and cost metadata sit cleanly at the end without obscuring the core statement.

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 and the body schema is exhaustively documented, so return values and parameters are adequately covered. The remaining gap is orientation within a large prognostics family: nothing explains why one would choose this over tertiary/minor progressions, which is what an agent most needs here.

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 100%, so the nested body, fields, precision, targetDate, converse and targetTime parameters are already documented in the schema. The description only obliquely echoes 'target date' and adds no format or semantics beyond it; baseline 3 applies.

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 verb (Calculate) and resource (secondary progressed chart) and pins down the technique with '(day-for-a-year)', which is a real differentiator. However, it never names or contrasts the adjacent progression siblings (tertiary, minor progressions) that an agent must choose between.

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?

No statement of when to pick secondary progressions over tertiary or minor progressions, nor any prerequisite (valid natal birth data, target date semantics). The agent is left to infer usage entirely.

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