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

Annotations already cover read-only/idempotent safety, but the description adds genuinely useful behavioral context: 'Past results only, never a forecast' sets expectations about the data's nature, and it clarifies the auth requirement ('same sign-in as get_my_vault'). It stops short of describing format or refresh behavior.

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?

Front-loaded with the core purpose and the descriptive clause is information-dense rather than padded. The single long clause is slightly crowded but every element 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 no parameters and no output schema, the description carries the load and does so reasonably, enumerating the reported dimensions (earnings, duration, pace, lock impact) and the read-only/historical nature. Return format specifics are the only 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?

The tool takes zero parameters, so the schema baseline of 4 applies; there is nothing for the description to disambiguate beyond confirming the implicit sign-in scope.

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 ('your own $VAULT position') and what it reports (RWA earnings, duration, pace, lock impact). 'Your own ... for the wallet you signed in with' implicitly distinguishes it from the general get_rwa_performance sibling, though it doesn't name that sibling explicitly.

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?

'Same sign-in as get_my_vault' and 'your own' imply usage context, and read-only framing is clear, but there is no explicit when-to-use versus when-to-use-the-alternative guidance (e.g., versus get_rwa_performance or get_my_vault).

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