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

Annotations already declare readOnly, idempotent, non-destructive, closed-world. The description adds genuinely non-obvious behavioral facts: a 3-credit cost with only successful calls charged, a free sandbox key returning a fixed sample, and determinism of output. It does not describe latency or output shape, but the output schema covers returns.

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?

Purpose is front-loaded in the first sentence, followed by scope, cost, determinism and an example. Every block earns its place, though the inline JSON example is long relative to the rest and could arguably be trimmed.

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 an output schema present and annotations covering the safety/idempotency profile, the description only needed to add cost, determinism and argument shape, which it does. The one remaining gap is that it never positions itself against the several sibling tools that overlap in purpose.

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 the optional time and the reduced-house-detail caveat. The description restates the referenceDate default (already in schema) but the worked example does clarify the nested birthData shape. Baseline 3 is appropriate since the schema does the heavy lifting.

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 a specific resource ('lifestyle guidance cards for each running daśā level') and enumerates the levels it covers (mahādaśā, antardaśā). An agent can tell it produces interpretive guidance rather than raw daśā periods, but it never names or distinguishes itself from sibling tools like get_dasha or interpret_domain, which occupy adjacent semantic space.

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?

It gives a default for referenceDate, which implies you can omit it, but offers no when-to-use/when-not guidance and no routing to alternatives such as get_dasha (raw periods) or interpret_domain (other interpretative output). The agent is left to infer which of the several guidance-adjacent siblings to call.

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