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

The annotations already declare destructiveHint=true and idempotentHint=false; the description adds real context beyond them by stressing 'one-time' (the code is consumed) and that quota is credited to the current account rather than an arbitrary one. It stops short of describing failure behavior for invalid or already-used codes or whether quota stacks, so it is not fully complete.

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 two short sentences followed by a minimal parameter note, with the effective outcome front-loaded; the Chinese restatement is redundant for an English reader but does not obscure the structure.

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 one-parameter mutation with an output schema and full annotation coverage, the definition supplies what an agent needs to select and invoke it. The remaining gap is error/edge-case behavior on invalid or reused codes, which the output schema cannot cover.

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?

There is a single required parameter with 100% schema coverage, so the schema already explains the code and its one-time nature. The description's abbreviated Args note largely repeats the schema text rather than adding format, source, or validation meaning.

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 first sentence names a specific verb and resource ('Redeem a one-time code') and states the concrete effect ('add API call quota to the current account'), which cleanly separates it from siblings like get_balance (read quota) and parse_video.

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 only implied: the agent can infer it should call this when holding a code, but there is no explicit guidance on prerequisites, when not to use it, or what to expect if the code has already been redeemed. No alternative tool is named, though none of the siblings is a real substitute.

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