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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, and the description legitimately adds matching semantics ('all meaningful query terms must match'), ranking order (exact names first, then themes/keywords), and the return payload (match reasons, canonical source links). That is useful behavior beyond the annotations.

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?

Four compact sentences covering ranking, supported domains, match semantics, ordering, and return content. Dense but each sentence carries information; the opening 'Rank English card names...' leads with mechanism rather than purpose, which is a minor front-loading weakness.

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 an output schema present the description need not detail returns, yet it still mentions match reasons and canonical links. For a read-only, idempotent search tool with all-optional params, the description plus schema and annotations give an agent enough to invoke it 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 0% across 3 params, so the description must compensate. It explains query semantics and empty-query behavior, and 'optionally by family' loosely gestures at the category enum, but the limit cap and the enum values themselves are left entirely to the schema, leaving gaps.

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 (rank/search) and resource (78 tarot cards) and enumerates the searchable fields (card names, topics, keyword synonyms, overview/guide text). It does not explicitly contrast itself with siblings get_card_meaning or get_tarot_spreads, which keeps it below a 5.

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?

Provides one concrete usage mode — an empty query lists cards, optionally by family — which implies how to browse rather than search. However, it never says when to use this over get_card_meaning or get_tarot_spreads, so usage is only implied.

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