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

Annotations already establish that the tool is read-only and non-destructive, so the description need not relitigate safety. It adds behavioral value by disclosing the full response field spectrum (Sanskrit names, Western equivalents, dates, symbols, Adityas, personality traits) and framing the output as complete and deterministic. This is meaningful context beyond the static read-only flag, especially given there is no output schema.

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 description is appropriately concise and front-loaded: the first sentence states exactly what the tool returns, and the second sentence immediately spells out use-case implications. There is slight overlap with the title (both mention listing all 12 Rashis), but the description earns its place by adding downstream usage guidance. It is shorter and more navigable than average.

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 simple read-only reference list with zero required parameters and a fully described schema, the description is largely complete. It tells the agent what data will be present and what the data is useful for, even without an output schema. The one notable gap is that it does not explicitly highlight the sibling get_vedic_astrology_rashis_id for the single-rashi case, but the naming convention and reference framing make the distinction transparent enough.

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?

The input schema fully documents the two parameters, with default values, examples, and complete descriptions; schema coverage is 100%, so the description does not need to re-explain them. The description does not add any extra color about lang behavior or compact encoding—everything parameter-wise lives in the schema already, so the description carries no added value here.

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 clearly identifies the action ('Get the complete list of 12 rashis') and enumerates the resource ('list of 12 rashis'), with specific returned content (Sanskrit names, Western equivalents, sidereal date ranges, symbols, governing Adityas, personality characteristics). It immediately stands apart from the sibling get_vedic_astrology_rashis_id because it explicitly is the all-rashis reference, not a single-entry lookup.

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 contextualizes when the tool is valuable: 'essential for zodiac sign lookup tables, astrology apps, and rashi-based UI components.' This emphasizes that it is a static reference list rather than a calculation, rather than anything about per-rashi lookup. It stops short of explicitly naming the sibling-by-ID tool as the alternative for single-rashi requests, so it is omitted a clear exclusion, but the context is otherwise clear.

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