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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds materially useful context: it operates strictly on saved profiles and requires a free AstroCalc sign-in, which is a real gating constraint an agent must know before calling. It does not say what happens when the profile is missing or ambiguous, which keeps it from a 5.

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?

Content is front-loaded and the enumeration of returned values is efficient. Minor waste: 'Read-only' duplicates the readOnlyHint annotation, and the trailing list of five sibling tools is long, though it does carry real routing value.

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?

With no output schema, the description takes on the job of describing return content, and it does so concretely (Moon placement, Chandrashtama, house occupancies, Sade Sati). Auth and profile prerequisites are covered. Only failure behavior for an unknown profile is unaddressed, which is minor for a read-only 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 description coverage is 100%, so both parameters are already documented, including that profile is a name from my_profiles or an id and that lang controls text language. The description adds no parameter-level detail beyond the schema ('counted from their Moon sign' describes computation, not an input). Baseline 3 applies.

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?

Names a specific output (today's planetary weather for one saved person, computed from the Moon sign) and enumerates exactly what is returned: Moon position and Chandrashtama status, Saturn/Jupiter/Rahu/Ketu house placements, and Sade Sati status. It is clearly distinguishable from natal-chart siblings like full_chart and my_kundli.

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?

Explicitly states the triggering conditions ('how today looks for them or someone saved, or whether today suits a plan') and the boundary case: only saved profiles work here, while birth details typed in chat route to free_kundli, kundli_milan, explain_dasha, full_chart and life_timeline. Alternatives are named with the condition that selects them.

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