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

The annotations already establish that this is a safe, idempotent read (readOnlyHint, idempotentHint, destructiveHint false), so the safety profile is covered. The description adds behavior beyond the annotations: it limits results to 'live' cards and warns that curated collections produce zero gaps, which prevents the agent from misreading an empty result as a bug.

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 with no filler: the core behavior comes first, followed by the one non-obvious caveat. Each sentence carries distinct information.

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?

An output schema exists, so the description is rightly silent on return shape. However, for a 5-parameter tool with only 60% schema coverage, the description leaves the required targetLang unexplained, which is a real ambiguity for a gap check that is inherently language-specific.

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 description's field list (translation, POS, pronunciation, examples, image) maps onto the fields parameter, but the schema already documents that parameter thoroughly, including the array-not-string warning and the ANY-semantics. The required targetLang parameter is undocumented in both places, and limit and the two collection selectors are not mentioned at all, so the description does not compensate for the remaining 40% coverage gap.

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 gives a specific verb and resource: it returns live Lingard cards in a collection that lack requested fields, and it enumerates which fields (translation, POS, pronunciation, examples, image). That is clear enough for an agent to understand the tool's job. It does not name its natural counterpart, lingard_fill_missing_card_fields, so the distinction between diagnosing gaps and fixing them is left to inference.

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 use case is implied (a gap audit that would precede lingard_fill_missing_card_fields), but the description never explicitly states when to use this tool instead of its sibling. The caveat that a curated collection always reports zero gaps is a genuinely useful usage signal because it tells the agent when results are not meaningful.

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