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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the bar is lower, and the description contributes the non-obvious constraint that this tool is reserved for the internal panel and should not be invoked directly. It does not add rate limits or error behavior, but the output schema covers return shape.

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 short sentences, zero filler, with the routing constraint front-loaded before the behavioral clause. Every phrase carries 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 return values need no explanation, and annotations cover safety. The remaining need for a single-param read tool is correct routing, which is fully addressed; only the card_id semantics are left implicit.

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?

One parameter with 0% schema description coverage, so the schema does not explain card_id; the description mentions 'a card's back' but never clarifies the id's meaning or source. The name card_id is largely self-evident, yielding a minimum-viable 3 rather than a full compensation.

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 concrete verb and resource ('Returns a card's back') and clearly marks itself as the panel-scoped variant distinct from the general sibling. It stops short of a 5 only because the actual output/behavior is stated in a single terse clause rather than fully characterized.

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?

Explicit caller restriction ('Used by Flash's study panel only; never call it yourself') plus a named alternative ('use show_answer') that resolves the ambiguity for a generic agent. Both when-to-use and when-not-to-use are stated directly.

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