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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive behavior, covering the safety profile. The description adds the cost trait ('Free') and lists return fields, but does not disclose auth needs, rate limits, or pagination—reasonable given the annotation coverage, yet still limited.

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 sentence that is front-loaded with 'Free.' and then lists the exact outputs. No filler, no repetition—every word 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 a rich output schema, full parameter documentation, and annotations covering safety, the description only needs to state the tool's value proposition. It does so succinctly and completely for a simple read operation.

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 fully documents the single required 'address' parameter with a format pattern and description. The tool description adds no further meaning about the parameter, so the baseline score of 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 specifies the resource (basket vault) and the exact data returned: NAV, holdings, weights, and rebalancing need. It lacks an explicit verb (e.g., 'Get') and does not differentiate itself from siblings like stocks_portfolio or stocks_basket, but an agent can still infer its read-only purpose.

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 word 'Free' conveys a clear cost guideline, and the purpose implies when to use it (to inspect vault state). However, there is no explicit when-to-use guidance relative to sibling tools or any when-not-to-use condition, leaving alternatives unaddressed.

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