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

Annotations provide readOnlyHint and openWorldHint, but the description adds substantial behavioral detail: an API key requirement, newest-first ordering, verified/pending sale statuses, buyer identity never exposing wallet, hosted vs seller-run data sources, and _untrusted fields. This is far beyond what annotations or schema reveal.

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 front-loads the core purpose and then packs a large amount of necessary semantics into a dense, semicolon-heavy sentence. It could be restructured for readability, but every phrase earns its place and no redundant filler appears.

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?

With no output schema, the description supplies the return contract: relevant fields, review_status meanings, trust boundaries, and the follow-up action of calling rate with purchase_id. For a one-parameter read-only tool, an agent has enough to invoke and interpret it correctly.

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 only one parameter, limit, and the schema covers it fully with a description that already says 'Newest first.' The tool description repeats that ordering but adds no new parameter semantics, so the baseline of 3 is appropriate.

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 opening phrase 'What you sold' states a specific verb and resource, and the body enumerates the return shape: buyer profile id and name, transaction hash, amount, and review_status. It also references related tools (rate, recordPurchase), helping distinguish it from siblings like myPurchases and myListings.

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 clear context: use purchase_id with rate(), and it distinguishes hosted listings from seller-run links that need recordPurchase. It does not explicitly contrast with myPurchases or other read-only sibling tools, but the 'what you sold' framing makes the primary usage clear.

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