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

The annotations already declare readOnlyHint=true and destructiveHint=false, so a safe read is understood. The description adds meaningful behavioral context by spelling out exactly what data is returned: symbol, tagline, category, dignity, keywords, etc. It does not mention rate limits or auth, but for a read-only lookup tool the transparency level is strong.

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 opens with the core action and resource, then gives a useful field list, and ends with usage examples. The use-case enumeration is slightly long and somewhat redundant, but it remains front-loaded and readable. It is appropriately sized for a tool that returns rich astrology data.

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, so the description must convey return semantics, and it does well by listing many of the expected fields and value types. It also clarifies how id and name inputs work. Minor gaps, such as explicit language fallback behavior and a stronger separation from sibling endpoints, are slightly missing, but the overall picture is complete enough for an agent.

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 has 100% coverage with detailed descriptions for all three parameters, including BCP47 language support and compact-shape semantics. The description repeats only a fragment of the id parameter's behavior and adds no new information beyond the schema. Since the schema already carries the parameter semantics, a baseline 3 is appropriate.

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 ('Retrieve'), a clear resource ('comprehensive planet interpretation'), and a distinct input contract (lowercase ID or case-insensitive name). It also lists the exact data fields returned, making the tool's purpose immediately recognizable and distinguishable from a generic list or sign-related tool.

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 practical use cases like 'birth chart readings', 'planet meaning lookups', and 'transit meanings', making it clear when to use this tool. However, it does not explicitly distinguish itself from the sibling 'get_astrology_planet_meanings' or state when the plural variant should be used instead, so it stops short of full exclusionary guidance.

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