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

Annotations already declare read-only and idempotent, so safety is covered. The description adds value by revealing output specifics: one per archetype, sorting by closeness, and including ownership/missing/cost details. No contradictions with 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?

A single, dense sentence that front-loads the key action ('Tournament decks') then efficiently details scope, sorting, and output content. No wasted words or redundant filler.

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 read-only tool with no output schema, this is nearly complete. It explains both the output (decks, missing items, cost) and ordering. Minor gaps: how 'closest' is measured isn't specified, and it doesn't state whether the collection source is the my_collection tool, but these are inferable from the sibling set.

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 67% (format and source have descriptions; limit has constraints). The description adds context that cost is involved, which ties to the source parameter, and implies limit controls the number of decks shown. This complements the schema without repeating it.

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 states a specific verb and resource: lists tournament decks the user is closest to completing, with details like ownership, missing cards, and cost. It clearly differentiates from siblings like get_meta_deck (single deck) or my_collection (card list) by focusing on buildable decks from the user's collection.

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 context is clear: it's for the signed-in user viewing their own collection, and the title 'Meta decks I can almost build' reinforces when to use it. However, it does not explicitly name alternatives or state when not to use it, though the sibling set makes this inferable.

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