Solar Return

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful operational context — the POST endpoint and a 50-credit Tier 3 cost — which annotations do not carry. It says nothing about rate limits, timeouts, or what happens if the year is omitted, so it stops short of a 4.

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 sentences lead with the core function, followed by compact bracketed metadata for group, endpoint and cost. Nothing is padded, though the group/endpoint lines are largely redundant with the tool name and add little for an agent.

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-value explanation is not required, and annotations cover safety. However, for a prognostics tool it leaves open the important operational question of how the target year is selected (year parameter is not in the required list, while the description implies it is needed) and provides no differentiation from the many other return/prognostic 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 100% and the single 'body' parameter is thoroughly documented in-schema (date/time/coordinates formats, timezone rules, house system letters). The description adds no parameter-level meaning — notably it does not clarify that the 'year' field in the schema is what 'a given year' refers to, or what default applies when it is absent.

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 precise verb+resource: find the moment the Sun returns to its natal longitude and return the full solar return chart. An agent can tell it apart from lunar or planetary return siblings by the explicit 'Sun'/'solar' focus. It doesn't name those siblings as alternatives, but the function itself is unambiguous.

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 when-to-use, prerequisites, or alternative routing is given beyond the phrase 'in a given year'. The description never says to prefer this over astroway_prognostics_lunar_return or astroway_prognostics_planetary_return, nor under what circumstances a solar return is the right technique.

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