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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine context by labeling the data 'public onchain data' and the profile link 'read-only', but says nothing about rate limits, error cases, or which chains are included.

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 information-dense sentence with the primary payload (balances) front-loaded and the secondary payload (profile link) trailing. It is slightly awkward as a verbless noun phrase, but no sentence is wasted.

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?

No output schema exists, so the description correctly enumerates what is returned (balances plus a profile link). Annotations cover safety and the schema covers the sole parameter; only the set of supported chains and pagination/response shape remain unstated, which is a minor gap.

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?

With a single parameter and 100% schema description coverage ('0x... wallet address'), the schema already carries the semantics. The description's 'any wallet's' adds no format or constraint detail beyond what the schema provides, so 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?

The description names the resource precisely (stock-token and cash balances per wallet) and adds scope ('every chain The River serves') plus a secondary return ('read-only River profile link'). It lacks an explicit verb and does not distinguish itself from siblings like fair_value, but the resource is unambiguous enough for an agent to select it.

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?

There is no statement of when to use this tool versus alternatives such as fair_value or list_stocks, and no prerequisites or exclusions. Usage is only implied by the resource name.

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