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

Annotations already declare readOnly, idempotent, destructive=false, and openWorldHint=false, so safety is covered. The description adds useful context that the tool performs a place/timezone resolution step before computation, but it says nothing about failure behavior for unknown place names, output determinism, or resolution errors.

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?

A single front-loaded sentence with the distinguishing mechanic (verified catalogue place + IANA timezone) stated before the benefit clause. No wasted words, though it is dense enough that it reads as one packed clause chain.

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 no explanation. However, for a four-required-parameter astronomical computation with 0% schema documentation, the description leaves the meaning of natalLagnaSign and the place-resolution contract unspecified, which is a meaningful gap for correct invocation.

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 0% across five parameters, yet the description only gestures at "place" and hints at date/time implicitly through "transits". Critically, natalLagnaSign (a 0-11 sign index) and the language enum are never explained anywhere a caller can see. The description does not compensate for the coverage gap.

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?

The description names a specific verb (calculates sidereal transits) and pins the key distinguishing mechanic: the place is a verified catalogue entry resolved together with its IANA timezone rather than raw coordinates. This separates it from generic transit tools like analyze_transit_activation, though it never names a sibling explicitly.

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?

"Avoiding manual coordinate and offset entry" implies the tool is the preferred path when the location is already in the catalogue, but there is no explicit when/when-not statement or guidance to call search_locations first for unverified places. Usage is inferable rather than stated.

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