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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds a genuinely useful output convention ('planet names carry an SR suffix') and the cost tier, but says nothing about latency, response shape, or the year-based scoping behavior beyond the one clause.

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?

Front-loaded with the core purpose in the first clause, followed by the definitional detail and the SR-suffix note. The [Group] and [Cost] tags are boilerplate metadata but earn their place by surfacing billing tier. No wasted sentences.

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 values need not be described, and annotations carry the safety profile. Combined with a 100%-documented schema, the description is sufficient for correct invocation, though it could do more to route the agent among the many A*C*G 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%, so the rich body schema already documents date/time/latitude/longitude, timezone handling, house system letters and the compact-mode fields/precision params. The description adds no parameter-level meaning beyond that, 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+resource: astrocartography computed for the solar return of a given year, defined as the moment the Sun returns to its natal longitude. This distinguishes it conceptually from the natal A*C*G sibling (astroway_geo_acg) and the return family, though it never names the sibling it differs from.

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?

Usage is implied by 'for the solar return of a given year' – an agent can infer it should be used when an SR-based map is wanted rather than a natal one. But there is no explicit when-to-use/when-not-to-use guidance and no alternative tool is named despite many close geo siblings.

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