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

The annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds only the word 'paid', which is a cost/access note, but lacks details on rate limits, output structure, or any nuances beyond the schema. With annotations present, this small addition warrants a mid-range score, but no contradiction exists.

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?

Three words cannot adequately describe a tool with 17 parameters and rich filtering options. While there is no redundancy, the text is under-specified; it sacrifices necessary detail for brevity.

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 complex screener with 17 parameters, a one-phrase description is completely inadequate. It does not explain what results look like, how filters work, or any prerequisites. The schema and annotations cover the data model, but the description itself fails to provide holistic context.

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?

All 17 parameters have descriptions in the schema, giving 100% coverage. The tool description itself mentions none of the parameters, but the schema fully documents them, so a baseline score of 3 is appropriate.

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 'Stock screener (paid)' essentially restates the tool's title with a parenthetical cost note. It lacks a verb and does not explain what the tool does (e.g., 'filters stocks by criteria'). This is a tautology rather than a functional description.

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?

No guidance is provided on when to use this tool versus any sibling tools like 'quote', 'search_symbol', or 'intraday'. The description only mentions that it is paid, which is a cost constraint, not a usage recommendation.

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