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

With no annotations, the description carries the disclosure burden. It clearly discloses the key behavioral trait: returns the active fund object or null if Manager Mode is not active. The 'authenticated user's' phrasing and read-style verb make the operation seem safe, though it does not explicitly state that no side effects occur.

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 short, purposeful sentences: the first names the resource, the second states the return contract. No filler, no restatement of the tool name, and the most important distinguishing detail ('Manager Mode') is front-loaded.

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?

For a zero-parameter getter with an output schema, the description is nearly complete: it identifies whose fund, the Manager Mode condition, and the null behavior. It could optionally mention activate_fund/deactivate_fund for mode management, but that is not needed to invoke this tool 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 zero parameters, so the schema is already complete and there is nothing for the description to clarify. The zero-parameter baseline of 4 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 states a precise verb ('Get') and a scoped resource ('authenticated user's currently active (Manager Mode) fund'), which clearly separates this from generic getters like get_fund and list_funds. The explicit null-return condition further defines what the tool does.

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 implies when to use the tool—when the caller needs the current Manager Mode fund—and the null condition conveys when no active fund exists. However, it does not name alternatives or say when to use get_fund/list_funds instead, so the guidance is inferred rather than explicit.

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