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

With no annotations, the description carries the full burden of behavioral disclosure. It only states high-level retrieval and comparison, but does not explain how the optional sector/exchange filters behave, whether all sectors are returned by default, or what the response looks like. This is a notable transparency gap.

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, front-loaded with the action verb ('Retrieve') and no filler. Every word contributes to explaining what the tool does and why it's useful.

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 simple snapshot tool with a well-covered schema, the description gives purpose and a use case, but it omits behavior around optional filters and return values. Given no output schema and no annotations, it is adequate but not thorough.

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 input schema fully describes all three parameters (100% coverage), so the baseline is 3. The description adds no extra parameter semantics—beyond 'various sectors,' it gives no guidance on how date, sector, or exchange interact or should be used.

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 retrieves P/E ratios for sectors and positions it for comparing valuation levels. However, it does not differentiate from sibling tools like getHistoricalSectorPE or getIndustryPESnapshot, so it is clear but not fully distinct.

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?

Provides a clear use case ('Compare valuation levels across sectors to better understand market valuations'), which tells when to use it. But it does not explicitly mention alternatives or when not to use this tool, leaving some ambiguity given the large number of similar market data tools.

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