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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the safety burden is off the description. The description adds that both applying and separating aspects are returned and discloses a 100-credit (Tier 4) cost, which is genuinely useful pre-call information, but says nothing about result volume, pagination, or lat/long input needs for this kind of calculation.

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?

One sentence of substance plus two bracketed metadata tags; the purpose leads and nothing is padded. Only minor drag from the metadata blocks, which are arguably infrastructural rather than descriptive.

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 structure need not be described, and the core operation is stated. Still, in a namespace with dozens of calendar and aspect tools, the description does not supply the disambiguating detail (Moon-to-planet only? all aspect types? transit vs. natal?) that would let an agent pick this tool confidently over its near neighbors.

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 50%: only fields and precision are documented, while the required year and month have no schema descriptions. The description's "within a date range" is the only hint about their meaning, and it is actually misleading since no day or time parameter exists in the schema, so the framing of a date range is never reconciled with the year+month inputs.

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), a specific resource (aspects the Moon makes), and a scope (within a date range, including applying and separating). This is clearly narrower than the generic astroway_calendar_aspects, though it never names that sibling to make the distinction explicit.

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?

"Useful for electional and horary work" gives a domain context, which implies when an agent would reach for it. However, there is no statement of when to prefer this over astroway_calendar_aspects, astroway_calendar_moon_voc, or astroway_aspects_aspect_timeline, all of which sit in the same decision space.

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