Booster box value

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

Goes well beyond the readOnly/idempotent/openWorld annotations by disclosing the price source (CardMarket EUR), the low/base/high range structure, the estimation caveat (pull rates are estimates, not a promise), the plan gate, and the per-call cost of 1 unit.

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?

Front-loads the core comparison and keeps the multi-mode behavior, caveats, plan requirement, and cost tight. Dense parentheticals but no wasted sentences; each clause 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?

With no output schema, the description compensates by describing return shape (range values, top cards, history) and data provenance. Annotations cover the safety profile and the plan/cost caveats are stated, leaving nothing essential for 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 coverage is 100%, so the baseline is 3. The description adds real semantics beyond the schema by explaining what each mode returns: listing all boxes vs. top cards and history for a specific slug. The default of 90 for history_days is already covered by 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?

States a concrete verb+resource: comparing sealed booster-box price against the estimated value of cards inside, with a clear scope (English Pokemon boxes passing Flipzi checks). It is implicitly distinguishable from card-level siblings like flipzi_get_price and flipzi_get_sold_comps, though no sibling is named explicitly.

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?

Gives explicit mode selection: omit `set` to list every published box, pass a slug (from the list) to get top cards and history. Also states the plan prerequisite (pro or higher) and cost (1 unit). No explicit exclusions against alternative tools, but the when-to-use conditions are clear.

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