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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds genuinely new operational context — the POST endpoint and a 20-credit Tier 2 cost — but says nothing about rate limits, response size, or caching.

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-loads the substantive chart description in the first line and keeps metadata in compact bracketed tags with no filler sentences. Efficient, though the bracketed block is somewhat boilerplate.

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 high-complexity 15-parameter astrology computation the description is thin: it never explains how to choose this varga versus its ~20 sibling varga tools, and it leaves the undocumented parameters to the schema. Output schema and annotations do cover return values and safety, mitigating but not resolving the gap.

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 only 33% for 15 parameters, so the description should compensate and does not. Its '[Required: date, time, latitude, longitude]' merely restates the schema's required array, adding no meaning for the ten under-documented parameters (zodiacType, houseSystem, cosmogram, etc.).

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 states the specific artifact ('Hora chart'), its analytical use ('wealth analysis') and its technical basis ('half-sign Sun/Moon division'), which goes beyond the bare name/title. Among the many sibling varga tools (D1, D3, D9, D60...), the D2/Hora identity is clear, though it does not explicitly contrast itself against those siblings.

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 when-to-use guidance at all — nothing says why an agent would pick the Hora chart over the other varga divisions available as siblings. The bracketed lines give endpoint, required params and cost, which are logistics rather than usage selection guidance.

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