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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false), so the description's job is supplemental. It adds real context beyond annotations: that the response is a composite of four otherwise-separate route answers, that `targetDate` defaults to now, and that yogas/doshas come back as a `present` list of those found. It doesn't mention the 50-credit cost or latency of composing four computations, which would be useful.

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-loaded with the most important fact (one call, full card), then the returned contents, then the route equivalence, then parameter caveats. Dense but no filler sentences; slightly heavy with backticked route/format tokens, but every clause carries information.

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?

An output schema exists, so return values need not be reproduced; the description still summarizes the payload shape usefully. Annotations cover safety, the schema covers the birth-data contract, and the description covers composition semantics and the targetDate default — an agent has everything needed to call this correctly for a 3-parameter tool.

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 coverage is 100%, so the schema already documents parameters and the baseline is 3. The description adds value beyond it by stating latitude/longitude are required, giving the accepted `time` formats, and noting `targetDate` defaults to now — a default that does not appear in the schema for that field. The `fields`/`precision` compact-mode params are left 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?

The description names a specific verb+resource (a kundli card in one call) and enumerates exactly what it returns: D1 lagna, nine grahas with sign names, Moon nakshatra/pada, running Vimshottari maha/antar, and Parashari yogas/doshas with a `present` list. It explicitly maps each part to the sibling routes it aggregates (/vedic/varga/D1, /vedic/dashas/vimshottari/antar, /vedic/yogas/parashara/full, /vedic/doshas/parashara/full), so an agent can distinguish it from those sibling tools without opening schemas.

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 'one call' framing plus the explicit equivalence to four individual routes tells the agent when this is the right pick (want the whole card, avoid four round trips) versus the narrower single-purpose siblings. It doesn't state exclusions (e.g., use a different tool for compatibility or transits), so it falls short of full when/when-not guidance, but the aggregation context is clear.

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