player_pack_purchases

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

With no annotations, the description carries the full burden and does so thoroughly. It discloses read-only behavior ('never purchases packs'), request characteristics ('Makes one logical GET request', 'Does not auto-fetch continuation pages'), parameter policy ('Required inputs reflect tool policy...', 'filters are forwarded as supplied; effectiveness not implied'), and response limits ('locally limited to 100 rows and 256 KiB, with truncation reported...', 'Oversized records are refused'). This is extensive and specific.

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?

The description is dense but every sentence carries a distinct operational fact: purpose, safety, request behavior, pagination, parameter policy, and response limits. It is front-loaded with the core purpose (first sentence) and then lists caveats. There is a minor typo ('GET request Does' missing punctuation), but no wasted words. Slightly verbose, yet justified by the number of behavioral disclosures.

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 tool with 2 parameters, no annotations, and no output schema, the description covers safety, request behavior, pagination, parameter effectiveness, and response limits. The main gap is the lack of explicit return-structure detail – it says 'Array responses' but doesn't state what fields/objects the summary contains. Still, the operational context is strong enough for an agent to call and interpret the tool safely.

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 0%, so the description must compensate. It maps parameters to roles: 'one player' (username) and 'optional edition' (edition). It adds critical caveats: required inputs reflect tool policy and measured upstream requirements, and declared filters are forwarded without implying effectiveness. This goes beyond the bare schema (minLength strings) to explain intent and limitations, though it doesn't detail expected value formats.

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 opens with 'Read the upstream pack-purchase summary for one player and optional edition' – a specific verb, resource, and scope. This clearly distinguishes it from sibling tools like purchase_stats, player_inventory, and player_balances, which serve different data needs. An agent can identify the tool's function without opening the 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?

The description implies usage: use it when you need a player's pack-purchase summary, and explicitly notes it 'never purchases packs' (so not for purchase actions). However, it does not name alternative tools or provide explicit when-to-use/when-not-to-use guidance relative to siblings like purchase_stats or cards_pack_data_wax. The context is enough for basic routing but lacks explicit exclusions.

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