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

No annotations are provided, so the description carries the full behavioral burden. It discloses that the tool is open with no key needed, that fields can be missing, and that ranking conditions behave relative to visible markets. This is meaningful context beyond a simple listing, though it does not describe the output shape or explicitly state read-only behavior.

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?

The description is three sentences long and front-loads the core purpose before adding usage instructions and a caveat. Every sentence adds value, with no redundant wording or repetition of schema information.

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 metadata tool with an output schema, the description is complete: it states what the tool returns, when to call it, that no authentication is needed, and an important behavioral nuance about ranking conditions. No critical information is missing for an agent to use it 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?

The tool has zero parameters Input Schema, and schema coverage is 100%, so there are no unknown parameters to document. The description appropriately notes that no key is needed, which complements the empty schema. Baseline for zero-parameter tools is 4, and nothing is missing.

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's purpose: listing every field that query tools accept, along with meaning, unit, and missingness. It explicitly names sibling query tools (query_cross_section, screen_universe, query_series) that this tool is a prerequisite for, distinguishing it from data-querying tools.

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 explicitly instructs the agent to call this tool before specific sibling tools, which is strong when-to-use guidance. It also adds a practical usage condition: percentile, z-score, and top_pct/bottom_pct conditions require a wide market slice to rank properly.

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