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

With no annotations, the description carries the full burden. It discloses that the tool returns percentage weights per sector and explicitly scopes it to ETFs, but it does not mention behavior for non-ETF symbols, data source, update frequency, or return format. It adds some value but lacks richer behavioral context.

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 sentences, with the second being an illustrative example. The description is efficient and front-loaded, though the example is somewhat optional. Still, it earns its place by reinforcing usage context.

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?

Given the tool's low complexity (one parameter, no output schema) and clear purpose, the description is adequate. It explains the core functionality and provides an example, but slightly more detail about return structure or limitations would make it fully complete. It is not as under-specified as tools in lower tiers.

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?

Schema coverage is 100% with 'symbol' described as 'Fund symbol'. The description adds minimal extra semantic value by implying the symbol should be an ETF, but does not provide format examples or additional parameter context beyond the schema.

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 clearly states the tool provides a breakdown of ETF sector weighting percentages, using a specific verb ('provides') and resource ('sector weighting'). It distinguishes itself from sibling tools like getFundCountryAllocation and getFundAssetExposure by specifically focusing on sector weights.

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 via an example (investor evaluating sector exposure), providing clear context. However, it does not explicitly mention alternatives or when not to use it, such as when needing country or asset allocation, leaving some room for ambiguity.

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