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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the safety profile is covered. The description adds real value beyond that: it promises deterministic output and proactively declares that KP ayanamsa and Placidus cusps are reported as unavailable pending independent validation, which shapes how an agent should interpret results.

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?

Two sentences with no filler, and the primary return content is front-loaded ahead of the caveat about unavailable data. Nothing redundant is repeated from the annotations.

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 10-parameter tool with two mutually exclusive input modes and a low schema coverage rate, the description omits the invocation guidance an agent most needs. An output schema exists so return values need not be explained, but the dual input paths and the absence of sibling differentiation leave significant gaps.

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 30% across 10 parameters, so the description carries a heavy burden and delivers nothing: no mention of date/time format, the place-vs-coordinates alternative, the IANA timezone requirement, or the timezoneOffset fallback. The critical anyOf branching (place alone, or latitude+longitude+timezone) is left entirely to the schema.

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-plus-resource: it returns Nakshatra star/sub/sub-sub lords, ruling planets, and significator evidence, framed as a 'KP structural preview'. An agent can tell this is KP-specific output. However, it never contrasts itself with adjacent siblings like analyze_nakshatra_profile or calculate_ayanamsa_chart, which cover overlapping territory.

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 only implied through the description of KP output; there is no explicit statement of when to prefer this over the many sibling chart tools. The one exclusion offered – ayanamsa and Placidus cusps unavailable until validated – does hint that agents needing those should look elsewhere, but no alternative is named.

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