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

No annotations are provided, so the description carries the full burden of disclosing behavior. It explicitly states that the response includes the calculation moment and warns that without it, a stale snapshot is indistinguishable from the current one. This is a useful behavioral nuance. It does not mention read-only nature, but that is evident from the purpose.

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 two sentences long, front-loads the core purpose, and includes a meaningful caveat in the second sentence. No filler or redundant wording. Every sentence earns its place.

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 is mostly complete. It highlights the critical timestamp nuance that an agent needs to understand the output. The lang parameter is fully covered by the schema, so its absence from the description is acceptable. No significant missing context for an agent to invoke the tool correctly.

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?

With schema description coverage at 0%, the description should compensate for the undocumented parameters, but it makes no mention of the 'lang' parameter at all. The schema already provides an enum and default, so the parameter is not confusing, yet the description adds zero meaning about how language affects the response or which values are accepted. Thus it fails to compensate for the low coverage.

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 clearly states a specific purpose: showing current positions of planets in signs and the current Moon nakshatra in this minute. The phrase 'в эту минуту' conveys real-time scope, which helps distinguish it from other astrological chart tools. However, it does not explicitly differentiate from siblings like panchanga that may also provide nakshatra, so it falls short of a 5.

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 description implies usage for current sky queries and emphasizes that the calculation timestamp is included, but it gives no explicit when-to-use or when-not-to-use guidance or alternative tool references. The 'this minute' framing is a clear contextual hint, but without exclusions or sibling comparisons, it stays at an implied level.

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