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

Beyond the readOnly and openWorld annotations, the description adds meaningful behavioral details: the URL is fresh for five minutes, the operation is free forever, entitlement failure returns `not_entitled` rather than a 402, and `wallet_signature` is required for proof of ownership. This is exactly the kind of context an agent needs.

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?

Four tight sentences, each carrying useful information: the endpoint, the freshness window, the entitlement semantics, and the auth requirement. The most important behavioral facts are front-loaded and 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?

For a read-only retrieval tool with an output schema and clear annotations, the description covers the purpose, entitlement edge case, URL freshness, and authentication prerequisite. An agent has everything needed to call it correctly and understand its result semantics.

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 100%, so the schema already documents all four parameters well. The description reiterates that `wallet_signature` is required and ties it to entitlement, but adds little beyond what the schema already provides.

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 clearly identifies the tool's action: wrapping `GET /api/r/:owner/:slug/v/:version` to fetch a fresh download URL for a version the wallet already owns. The title and 'Never sells anything' distinguish it from purchase and other sibling tools.

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 explicit usage context: use it when the wallet already bought the version, it is free forever, and it works even after the listing is retired. It also explains the `not_entitled` case, making it clear when the tool is not applicable, though it does not name sibling alternatives explicitly.

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