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

Annotations already carry readOnly/idempotent/non-destructive, so the bar is lower. The description adds genuinely useful behavioral details: Rahu/Ketu default to Mean node, a clean Abhijit window excluding Rahu/Gulika/Yamaganda overlap, the gender-sensitive yoga behavior, and the 'Data only — no verdict' boundary. These are beyond what annotations state.

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 compact for the amount of content it covers. It front-loads the primary purpose (transit snapshot for a given date vs natal chart), then lists return sections and key behaviors. It could be a touch shorter, but every clause adds information about scope, defaults, or exclusions.

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 complex tool with 16 parameters and no output schema, the description covers the main return categories, the default node behavior, and the no-verdict boundary. It doesn't spell out every default (target_time default, event_place default), but the schema already documents those defaults, so the description needn't repeat them. The main gap is not describing the shape of the transit_charts output, but the schema and the description together are adequate.

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 100%, so the schema fully documents all 16 parameters. The description restates a few schema concepts (node_type default, gender optionality) but doesn't add much new meaning. It correctly orients the agent to the birth vs target_date distinction, but the schema already does that. Baseline 3 is appropriate.

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 is specific: it names the resource (planetary transit snapshot vs natal chart), the date (target date vs birth), and enumerates concrete content: panchanga, muhurta windows, 9 planets, Tara Bala, D-1/D-9 charts, node behavior. It clearly distinguishes itself from get_gochara_range and other astrological siblings by focusing on a single target date.

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 clearly states what data is returned and that no verdict is provided ('Data only — no verdict'), which tells the agent when not to use it for interpretive judgment. It also mentions node_type='true' for True nodes, implying the default Mean behavior is the common case. It doesn't explicitly name alternatives, but the richness of the content and the date-vs-range distinction vs get_gochara_range is implicit.

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