Hyleg & Alcocoden

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is free. The description adds genuinely useful non-annotation context: it is a POST to /v1/hyleg and costs 20 credits at Tier 2, which lets an agent reason about spend before calling. It stops short of noting anything about computational assumptions or the optional custom dignity tables.

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 front-loaded sentence with the payload first, followed by a compact bracketed metadata block (group/endpoint/cost) that is scannable rather than prose bloat. Slightly more could be spent on sibling routing rather than on redundant group metadata, but nothing is wasteful.

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 input schema is exceptionally detailed, so return values and parameter formats need not be restated. The description covers what is computed and at what price, which is sufficient for a read-only calculation tool; the only real hole is disambiguation from overlapping longevity/Hyleg siblings.

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 effectively 100%: the body object, timezone, timezoneOffset, ayanamsa and houseSystem all carry detailed descriptions, including the rejection of short-form field names and the I/i house-system case sensitivity. The description itself adds no parameter meaning beyond the top-level note that the body is 'Natal chart plus the hyleg method', so the 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 specific resources (Hyleg/apheta and Alcocoden), and even glosses both technical terms so an agent unfamiliar with Hellenistic astrology understands what is produced. It does not, however, distinguish this from the very similar sibling astroway_hellenistic_hand_longevity_hyleg, leaving a genuine ambiguity unresolved.

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 phrase 'using traditional Hellenistic method' implies a doctrinal context but gives no when-to-use trigger, no prerequisites, and no exclusions. With at least one close sibling (astroway_hellenistic_hand_longevity_hyleg) plus astroway_dignities_almuten in the same group, the description should have said which one to pick; it doesn't.

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