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

Annotations already cover readOnlyHint=true and destructiveHint=false, so the description need not restate safety. It adds useful context: the deck is user-scoped ('one of the user's decks') and the return includes both cards and a NextLang link. It stops short of describing errors or pagination, but that is minor for this tool.

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 front-loaded sentences with zero redundancy: first states the primary action and output, second gives parameter sourcing. Nothing could be trimmed without losing value.

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?

For a simple two-parameter, read-only getter, the description fully supports selection and invocation: it states what is returned and where to get valid parameter values. No output schema exists, but the description gives the high-level return shape (cards and link), which suffices.

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 coverage is only 50% (deckId lacks a description), so the description compensates by defining deckId as identifying one of the user's decks and by giving provenance for both parameters via 'Get deckId and platform from list_decks'. This adds real meaning beyond the schema.

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 uses a specific verb ('Returns') and a specific resource ('cards of one of the user's decks and its link on NextLang'), clearly distinguishing it from sibling tools like list_decks (which lists) and get_deck_file (which returns a file). The scope is precise: one user-owned 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?

It gives a clear prerequisite: 'Get deckId and platform from list_decks', which tells the agent exactly how to obtain valid parameters. It does not explicitly state when-not-to-use or name alternatives, but the context is unambiguous.

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