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

With no annotations provided, the description must carry the behavioral disclosure burden. It does state the scope ('this moment') and the main returned elements (planets by sign, Moon nakshatra/pada, tithi), which makes the read-only snapshot intent clear. However, it omits any mention of timezone/default time source, astronomical system, or output precision, leaving some behavioral ambiguity.

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?

The description is a single compact sentence that front-loads the most distinguishing information: real-time sky without a personal chart. Every phrase contributes substance, and there is no redundant or filler content.

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?

For a tool with one optional parameter and an output schema, the description covers the core idea and principal return content. Still, it leaves out usage guidance versus the closely related 'panchanga' tool and does not specify time or location assumptions, so an agent could call it with incomplete context.

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% and the description does not explain the 'lang' parameter. The parameter name and enum values (ru/en) make its language-selection meaning reasonably inferable, but the description adds no semantic value beyond that. The optional nature and default reduce the impact of this 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 identifies the resource clearly: the current sky without a person's chart, listing the included elements (grahas by signs, Moon nakshatra with pada, tithi). It distinguishes itself from natal-chart tools via 'без карты человека', but lacks a direct action verb and does not explicitly differentiate it from the sibling 'panchanga'.

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?

There is no explicit guidance about when to use this tool instead of alternatives. The phrase 'without a person's chart' implies it is not for natal-chart calculations, but it never names 'panchanga', 'astro_context', or other siblings, nor does it state the conditions that should lead an agent to choose this tool.

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