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

With the annotations already disclosing readOnlyHint=true and destructiveHint=false, the description appropriately adds only non safety behavioral detail: it states the measurement from bhava vijar sandhyas, identifies the specific malplaced-case it corrects, and previews the return shape plus the moved-flag affordance. It could add error/style consideration but for an idempotent compute there is nothing hidden to be cautions around; no corrective indications appear.

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 first three sentences are genuinely front-loaded and dense: purpose, motivation, and return contract in order. But the trailing keyword list — 'Bhav Chalit API, Chalit Kundli calculator, bhava chalit chart, Sripati house cusps, cusp based house chart Vedic astrology' — is SEO noise that costs tokens without helping agent - a clear violation the 'every sentence earns its place' test.

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?

Even though there is no output schema, the description compensates by enumerating the result contract — twelve bhava boundaries with madhyas and spans, both frames for every graha, and a moved flag. Combined with a trait that fully explains the 10-parameter inputs (including time-critical flags for Lagna and the timezone behavior), the agent has a practical profile to call it correctly; only a depth like error/Didation is not called out.

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%; every param — date, time, latitude, longitude, timezone, ayanamsa, focus, compactice, lang, ayanamsaValue — has a rich description, so the baseline of 3 applies. The tool description adds no supplemental or per-hmm parameter detail, which is acceptable given the heavy lifting the schema already does for the agent.

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 and resource ('Calculate the Bhav Chalit chart'), pins down the algorithm as unequal Sripati bhava cusps versus whole sign, and explicitly contrasts itself with the Rashi (D1) chart — which is the sibling tool post_vedic_astrology_birth_chart. An enumeration of the output (cusp bounds, bhave madhyas and splans, every graha in both frames, and a moved flag) leaves zero ambiguity about what the tool does.

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 context note that practitioners check the Chalit chart before reading a house results, house lordship strength its transit effect gives a concrete when-to-use trigger, and the contrast with the Rashi chart's whole-sign behavior makes the when-not-to-use condition reasonably clear. The downside is that no sibling is named and the exclusion is only implied by contrast, not stated directly as a would-to-use-this-alternative rule.

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