player_energy_purchase_information

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

No annotations are provided, so the description carries the full burden. It comprehensively discloses behavior: 'never purchases energy,' 'Makes one logical GET request,' 'Does not auto-fetch continuation pages,' 'Array responses are locally limited to 100 rows and 256 KiB,' 'truncation reported in text and metadata,' and 'Oversized records are refused without partial fields.' This is exceptional behavioral detail for a read tool.

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 front-loaded with purpose and safety but includes two boilerplate sentences ('Required inputs reflect tool policy...' and 'Other declared filters are forwarded as supplied...') that add little value for this specific tool and may confuse given the schema allows no other filters. These could be trimmed without losing meaningful 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?

For a single-parameter read tool with no output schema, the description covers key operational behaviors: read-only, pagination, response limits, truncation, and refusal policy. It does not describe the shape of purchased-energy/tier data, but that is acceptable without an output schema. The core calling constraints are fully covered.

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?

The only parameter, username, is not explicitly defined beyond the schema's minLength. The phrase 'for one player' implies it identifies a player, but no format, example, or additional semantics are provided. The boilerplate about 'Other declared filters' is misleading because additionalProperties is false, so no other filters exist. Schema coverage is 0%, so the description should compensate more.

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: 'Read purchased-energy and purchase-tier information for one player.' It also explicitly says 'This tool never purchases energy,' which distinguishes it from any mutation tool and clarifies the read-only intent. This differentiates it well from sibling tools like player_pack_purchases or player_balances.

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 gives context that this is a read-only informational tool, but it does not explicitly state when to use it over alternatives or name any sibling tools. The 'never purchases energy' statement is a constraint rather than usage guidance, and there are no exclusions or selection criteria beyond that.

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