Crystals: Full Directory

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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds that it is a static reference dataset returning taxonomies, but says nothing about result size, entry count, or whether the full directory is paginated — meaningful gaps for a tool billed at 5 credits.

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?

Two sentences of substance plus compact bracketed metadata (group, endpoint, credit cost). Content coverage is front-loaded ahead of the taxonomy note, and nothing is padded; the cost line is genuinely useful for an agent doing budget-aware planning.

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?

With zero parameters, full annotation coverage, and an output schema already present, the description only needed to convey what the dataset spans — which it does by listing the tag dimensions. The one omission is scale/cost trade-off guidance for a 'full directory' call, which is minor given the output schema documents the return shape.

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 tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. The description correctly conveys that filtering happens downstream via related tools rather than via inputs 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?

States a specific resource ('Reference list of crystals') and enumerates the descriptive fields it carries (chakra, zodiac, planet, element, hardness, purpose), so the agent knows what it returns. It stops short of naming the sibling endpoints (astroway_esoteric_crystals_by_chakra_chakra, _by_purpose_purpose, _recommend), so differentiation is only implied by 'taxonomies for filtering'.

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 phrase 'Returns chakra and purpose taxonomies for filtering' hints this is the lookup you call before using the filtered siblings, but the routing is never made explicit. There is no when-to-use/when-not-to-use statement and no mention that the by_chakra / by_purpose / by_zodiac tools exist for narrowing.

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