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

With no annotations, the description carries the behavioral disclosure burden. It reveals a key trait: results are scoped to registered/linked users and are board-specific rather than global. It does not mention output shape, tie-breaking, or update frequency, but for a simple ranked list the provided scope caveat is meaningful.

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 focused sentences front-load the core purpose and then clarify the population limitation. There is no filler or repetition of schema details.

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?

The definition adequately covers what the tool ranks and the population it covers, which matters for correct invocation. However, with no output schema and no annotations, a description of the return shape or example result would improve completeness; the current description leaves some ambiguity about what the agent will receive.

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 schema already documents all three parameters, including the metric enum with its meanings and limit/offset constraints. The description reinforces the metric semantics by listing total RAP, copies, and average lifetime appreciation, but it does not add substantial meaning beyond what the schema already provides.

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 a specific resource ('biggest Roblox Limited portfolios RBX Invest tracks') and a clear action ('rank'), and breaks down what ranking means: total RAP held, copies held, or average lifetime appreciation. It also scopes the tool to tracked/linked users, distinguishing it from a global player ranking.

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 useful context: this is a leaderboard for RBX Invest users only, not all Roblox players, so an agent can infer it is not appropriate for global rankings. However, it does not explicitly name alternatives like rank_creators or get_player_holdings, nor does it provide a when-to-use versus when-not-to-use comparison.

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