HD Transits

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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds materially new context: the HTTP endpoint, the 50-credit Tier 3 cost, and what the overlay actually produces (combined defined centers and channels) — cost and endpoint are not derivable from any structured field.

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 carrying the core behavior, followed by compact metadata lines for group, endpoint and cost. No filler, though the bracketed metadata is slightly detached from the prose.

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?

With an output schema present, return values need no explanation, and annotations cover safety. However, 'current' is ambiguous — the body actually requires an explicit date/time/lat/lon that define the transit moment, so an agent could wrongly assume the tool returns live transits for 'now'. A clarifying sentence would close that gap.

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 (date, time, latitude, longitude, timezone, houseSystem, natal* fields) are already documented in detail. The description only adds the framing that the natal fields enable an overlay — helpful but thin against a schema that already does the heavy lifting. Baseline 3.

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 current Human Design transit activations') and adds the optional natal overlay, which pins down the combined-centers/channels output. The 'Human Design' framing distinguishes it from the western sibling astroway_prognostics_transits, though it never names that sibling directly.

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 'Optionally overlay on natal chart' implies the two modes (bare transit vs. overlay), which is useful conditional guidance. But there is no explicit when-to-use vs. when-not, and no routing to the closest alternatives (astroway_hd_human_design for the natal chart itself, astroway_prognostics_transits for western transits).

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