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

Annotations already declare a safe read (readOnlyHint=true, openWorldHint=false), and the description adds genuine behavioral context beyond them: valued amounts are suppressed when the owner opted for privacy, and 'estimated value' is defined as floor minus a typical sell discount. The only gap is nothing about freshness/caching or sort order of collections.

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?

A single front-loaded sentence that names the resource and scope first, then enumerates the returned fields, then the caveat. It is dense but every clause carries information; only the 'floor less a typical sell discount' phrasing is slightly circuitous.

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 input schema, no output schema, and security covered by annotations, the description must describe the return shape and it does: grouping by collection plus count, floor, estimated value, and cost basis. Minor omissions like ordering or whether empty/hidden collections are included remain, but an agent could call this 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 are no parameters, so per the baseline this lands at 4. The description correctly signals that no targeting input is needed by specifying the owner's linked wallets as the implicit scope, which prevents an agent from hunting for an address parameter.

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 resource ('the NFTs the link owner holds across their linked wallets') plus the exact aggregation ('grouped by collection') and the fields returned. This clearly separates it from address-scoped siblings like wallet/collection and from my_activity/my_wallets.

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 implied rather than stated: with zero parameters it implicitly acts on the caller's own linked identity, which helps an agent infer it needs no targeting. But there is no explicit when-to-use or when-to-prefer-a-sibling guidance (e.g. vs. my_activity for trade history or wallet for an arbitrary address).

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