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

Annotations already declare readOnly=true, idempotent=true, destructive=false, and openWorld=false, so the safety profile is fully covered by structured data. The description adds the deterministic behavioral traits an agent needs: fixed size (54 entries) and deterministic ordering, which imply stable, repeatable output. It stops short of any rate-limit or failure-mode detail, deferring instead to a docs URL.

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?

Front-loaded with the payload summary, then clearly sectioned by WORKFLOW, INPUT CONTRACT, and DO NOT CONFUSE WITH, which makes it easy to scan. Slightly verbose in the field enumeration and the 'BEFORE: None — standalone catalogue' line carries little weight, but every section is purposeful.

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?

A read-only catalogue with an output schema, full annotation coverage, and one well-documented parameter needs little more than routing guidance, which this provides. Output values need not be re-explained given the output schema, yet the description still lists them usefully, and the error/output contract is linked.

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% and there is only one optional enum parameter (response_format), whose schema description already explains both values. The prose adds no syntax or format detail beyond what the schema provides, so the baseline 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?

States a specific verb and resource (returns all crystals) plus scope specifics: the exact count (54), the sort order (alphabetical), and a full inventory of the fields each entry carries. It also explicitly names the sibling tools it is not, so an agent can distinguish the full catalogue from the single-crystal and filtered variants.

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 BEFORE/AFTER block gives explicit sequencing, and 'DO NOT CONFUSE WITH' lists three sibling tools with the distinguishing condition for each (single crystal by name, filter by Vedic planet, recommendations by zodiac/chakra/intention). It also states the input contract (no required parameters). Nothing is left to inference.

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