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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavior: the feed is cursor-paginated and enumerates the event types returned (sales, listings, offers, transfers, mints). It omits details like rate limits or return ordering, keeping it short of a 5.

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?

Two dense sentences with zero waste: the first front-loads purpose and scope, the second handles disambiguation. Every clause 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?

With an output schema present, return values need no explanation, and annotations cover the safety profile. The description supplies purpose, scope, pagination behavior, event coverage, and sibling routing, which is complete for an agent to select and invoke this tool.

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 six parameters including the identifier and cursor. The description restates the identifier options (wallet/ENS/username) and mentions cursor pagination but adds no format or constraint detail beyond what the schema provides. Baseline 3 applies.

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?

States a specific verb (Fetch), resource (OpenSea NFT-event feed), and scope (a profile identified by wallet/ENS/username), plus the event categories returned. It also names the sibling tools it is distinct from, so an agent can separate it from opensea_collection_activity, opensea_item_activity, and opensea_activity without opening schemas.

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?

Explicitly routes the agent: use opensea_collection_activity or opensea_item_activity for scoped activity, and opensea_activity for the broader feed, making clear this tool is the profile-scoped option. The alternatives and the conditions selecting them are both stated.

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