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

The annotations already signal readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the full return inventory — name, zodiac range, ruling planet, presiding deity, symbol, personality traits, and traditional remedies including mantras, gemstones, and rituals. It does not disclose edge-case behavior such as error responses, but for a safe lookup with annotations in place, the transparency is solid.

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?

A single front-loaded sentence that leads with the verb and target, then expands into the return fields that matter, with no fluff or repetition of the schema. Every clause carries useful 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?

For a read-only single-resource fetch with no output schema, the description tells the agent what it will get back in some detail, and the schema enum enumerates all 27 allowed IDs. The only real gap is that it does not cover error behavior (e.g., invalid ID) and does not mention any response format, but overall an agent can confidently invoke and interpret the result.

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%: id is fully documented with an enum of 27 slugs, lang explains BCP 47 behavior and the 'field with no translation returns English' fallback, and compact explains lossless columnar shapes and token savings. The description adds no additional per-parameter meaning, so the baseline of 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?

The description states a specific verb and resource: 'Get detailed information for a single nakshatra (lunar mansion) by its ID slug.' It clearly identifies the object of the lookup, and the word 'single' distinguishes this from the sibling collection tool get_vedic_astrology_nakshatras. The list of returned content (name, zodiac range, ruling planet, deity, remedies, etc.) further pins down exactly what this 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 description gives a clear usage context: call this tool when you need one nakshatra's detail and have an ID slug in hand. The word 'single' implies the contrast with the list variant, but it never explicitly names get_vedic_astrology_nakshatras as the alternative for fetching all nakshatras, nor does it state when not to use this tool. So it has clear context but no explicit exclusions.

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