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

Annotations already declare this as read-only and non-destructive, so the description adds value by disclosing behavior not in the annotations: newest-first ordering, inclusion of language pair and link, and the total count beyond listed results. This gives useful context about what the tool actually returns.

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?

The description is front-loaded with the core listing behavior and then adds only high-value use-case guidance. Every sentence earns its place; no filler or repetition of schema details.

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 no output schema, the description explains the main return aspects (deck, language pair, link, total) and gives real usage contexts. It lacks an exact response shape or explicit platform-filter guidance, but the provided details are sufficient for safe and correct invocation.

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%, so the baseline is 3, but the description adds meaning beyond the schema by explaining how filters relate to counting questions and by clarifying that query is the only way to reach older decks. This enriches the parameter usage guidance.

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 action ('Lists the user's most recent NextLang decks, newest first') with a clear resource and key scoping details. The description also differentiates when to use it for counting, searching, showing, and post-generate verification, which separates it from siblings like get_deck and generate_deck.

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 explicit when-to-use guidance: answer 'how many decks' questions, filter rather than opening decks one by one, use query to find older decks, and check after a failed generate_deck call. This is actionable direction with implied alternatives and exclusions.

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