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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is fully covered. The description adds the credit cost (20, Tier 2) and that a built-in lot set is used when none is supplied, which is useful but modest additional context; it says nothing about formula syntax or error behavior for invalid custom formulas.

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 plus compact group/cost metadata; nothing is padded. The metadata lines are useful but arguably belong in structured fields rather than the description body.

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 annotations cover the safety profile, so the description need not explain return values. Stating what is returned (standard lots plus any custom formula) and the credit tier is sufficient for an agent to invoke this correctly.

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% and the schema itself richly documents body, timezone, houseSystem, fields and precision, so the schema carries parameter meaning. The description only implies that custom lots are optional via 'any custom formula', adding little beyond the schema's own 'built-in set is used when omitted' note.

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 and resource ('Calculate Arabic parts (Lots) from a natal chart') and lists outputs (Fortune, Spirit, custom formulas). It is clear on its own, but never distinguishes itself from the many sibling points/aspects tools such as astroway_aspects_midpoints or astroway_aspects_antiscia.

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 guidance on when to choose this over sibling tools or what prerequisites exist beyond the generic '[Group: Aspects & Points]' tag and cost line. The agent must infer usage purely from the name and one sentence.

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