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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds valuable context beyond those: it returns exactly 50 records, sorted alphabetically, and enumerates all content categories (chakra, planetary assignments, healing properties, origins, affirmations, cautions). It also links to the full output and error contract, which covers error handling beyond what annotations provide.

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 core behavior is front-loaded in the first sentence, followed by a concise list of included data. The WORKFLOW, INPUT CONTRACT, and DO NOT CONFUSE WITH sections are clearly labeled and add distinct value. It is slightly verbose for a no-parameter tool, but every sentence serves a disambiguation or contract purpose, so it is not wasteful.

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 list endpoint with zero required parameters and full schema coverage, the description is complete: it states the exact result size and ordering, enumerates response content, names related tools, gives follow-up workflow, and points to the error contract. An agent has everything needed to decide when and how to 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 description coverage is 100% — the only parameter, response_format, is fully documented with enum, default, and explanatory text. The description's 'No required parameters' reinforces the contract but doesn't add new meaning beyond the schema. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 opens with 'Returns all 50 crystals in the database sorted alphabetically' — a specific verb, resource, and scope. It also lists the detailed fields returned and explicitly differentiates itself from sibling tools via the 'DO NOT CONFUSE WITH' section, so an agent can clearly understand 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 'WORKFLOW' section states there is no prerequisite and names the natural follow-up tool (asterwise_get_crystal_by_planet) for filtering by Vedic planet. The 'DO NOT CONFUSE WITH' section explicitly contrasts this catalogue tool with asterwise_get_crystal, asterwise_get_crystal_by_planet, and asterwise_get_crystal_recommendations, giving clear when-to-use and when-not-to-use guidance.

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