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

Annotations already establish read-only, idempotent, non-destructive behavior, so the description's job is to add context — which it does by detailing the nine-planet output with sign, degree, house, nakshatra/pada, and D9 sign, and by flagging that house data depends on birth time. It does not cover any auth or rate-limit behavior, but none is evidently relevant here.

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?

Dense but every sentence carries load: synonyms first, then return contents, then the routing rule, then prerequisites, then exclusions. Front-loaded and free of filler.

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?

There is no output schema, but the description compensates by enumerating the returned fields. Combined with the routing and exclusion guidance, an agent has everything needed to select and invoke this tool correctly.

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 baseline is 3; the description adds real meaning by explaining the conditional role of birth_time (needed for houses) and clarifying that birth_place is a town/city with region or country. That goes beyond the schema's format-only descriptions.

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+resource ('Vedic birth chart') and enumerates the user phrasings it covers (kundli, janam kundali, sidereal chart) plus the exact output contents (signs, houses, nakshatras, rising sign). This clearly separates it from siblings like vedic_rising_sign or moon_sign_nakshatra.

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 routes narrower requests ('rising sign, Moon sign, dasha, Manglik') to other tools and states exclusions ('Do not use for Western/tropical charts or daily horoscopes'). It also gives the prerequisite-filling instruction ('ask if missing') for a required input.

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