player_energy_purchase_information

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

With no annotations provided, the description carries the full behavioral burden and does so thoroughly. It discloses side-effect freedom ('never purchases energy'), network behavior ('one logical GET request and does not auto-fetch continuation pages'), response limits ('100 rows and 256 KiB'), truncation reporting, and refusal of oversized records without partial fields. This is rich, non-obvious behavioral context.

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 the core purpose and contains useful behavioral details, but several sentences are generic or inapplicable. 'Required inputs reflect tool policy as well as measured upstream requirements' is vague, and 'Other declared filters are forwarded as supplied' is misleading given the schema only has username and additionalProperties false. The content is organized but not every sentence earns its place.

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 simple one-parameter read tool with no annotations and no output schema, the description is largely complete: it covers side effects, pagination behavior, response size limits, truncation, and refusal behavior. It does not describe the exact return fields or error/auth expectations, but these are not critical given the tool's simplicity and the absence of an output schema.

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, but it only adds that the request targets 'one player,' implying username identifies that player. It also says required inputs reflect tool policy and upstream requirements, which is vaguely useful but does not explain username format, constraints, or how it relates to purchase-tier data. The 'other declared filters' sentence is not applicable because the schema has no other properties.

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 a specific verb and resource: 'Read purchased-energy and purchase-tier information for one player.' The explicit statement 'This tool never purchases energy' further differentiates it from any purchase-like sibling, so the agent can identify the read-only intent and single-player scope without ambiguity.

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 provides clear usage context: it is for reading information about one player, never purchasing energy, and it performs a single GET without auto-fetching continuation pages. It does not name an alternative sibling tool or state explicit when-not-to-use conditions beyond 'never purchases energy,' but the context is clear enough for correct selection.

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