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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, yet the description adds real context beyond them: the checkout link requires a human to open it, sign in and pay on Stripe, and nothing is purchased by the call itself. That clarifies the link is a handoff, not an automated transaction. No rate-limit or error behavior, but the key behavioral surprise is disclosed.

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-loaded with the primary verb and resource in sentence one, then the conditional game behavior. The closing 'Read-only: nothing is bought by calling this' slightly overlaps the earlier Stripe sentence, but the reinforcement is intentional and cheap.

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 must carry the return-value burden, and it does: it enumerates price, guaranteed plays, days, placements, refunds, free boost line, boostability and checkout links. For a static read-only plan listing, little is missing; only exact response shape/format is unspecified.

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% and the single 'game' parameter is fully documented as a play link, Foundplay page link, or slug. The description only restates 'Given a game' and notes the conditional boostability output; it adds no format, matching or validation detail beyond the schema. Baseline 3 applies.

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 verb (Lists) and resource (Boost plans / paid promotion) and enumerates the exact contents: price, guaranteed plays, days, placements, refunds, free boost line, plus conditional boostability and checkout links. An agent can distinguish this from check_game and get_listing_link without opening any schema.

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?

Usage is implied ('Given a game, also says whether it can be boosted') but the description never states when to call this versus the siblings check_game or get_listing_link, nor any exclusions or prerequisites. Adequate but leaves the routing decision to inference.

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