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

Annotations already declare this is a read-only, idempotent, non-open-world call, so the safety profile is covered. The description adds meaningful context: lists are 'at the real checkout price,' leaving_game_pass covers a 30-day window with a buy-instead price, and results are ranked. It stops short of describing ordering criteria or pagination behavior.

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 triggering questions before the mode enumeration and the sibling exclusion; every sentence carries information. Slightly dense with three example questions and three mode definitions in one block, but there is no 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?

There is no output schema, and while the description implies each row carries a price and a ranking, it does not say what fields come back or how ties/limits behave. For a discovery tool with full schema coverage and annotations, this is nearly complete but leaves the return shape implicit.

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, but the description genuinely enriches 'kind' by explaining what each of the three values returns (tier currency display, all-time low, 30-day departure with fallback price). It adds no extra detail on limit, region, or currency 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?

States a specific verb (list/rank) and resource (deals) and defines the three modes by name. It explicitly distinguishes itself from the sibling get_cheapest_way_to_play, so an agent can route between them without opening schemas.

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?

Opens with concrete user questions it answers, giving the agent clear trigger contexts, and closes with an explicit exclusion plus the correct alternative tool for a specific game. When/when-not/alternative are all present.

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