Stock Screener (Technical)

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

Annotations already cover read-only, idempotent, and non-destructive safety. The description adds contextual behavior: data is real-time, crossovers are 'crossover today', filters combine with AND logic, and market_cap_basic is in absolute rupees rather than crores. This meaningfully extends beyond the annotations.

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 dense but organized: purpose, alternate tool, filter syntax, operations, fields, unit warning, and example. It is front-loaded with the core action and routing, and the long field enumeration is directly necessary for correct invocation. No filler sentences exist, though it could be tighter if a reference document were available.

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 no output schema, the description should explain what the tool returns. It never describes the response shape, default columns, or result container, which is a clear gap given the columns and limit parameters. The extensive input guidance makes it adequate, but the missing output semantics prevent full completeness.

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 80%, establishing a baseline of 3. The description significantly enriches parameter understanding by defining the filter object shape, enumerating all operations (including in_range and crossover semantics), providing a full field vocabulary, and giving a concrete example. The only minor inconsistency is marking filters as REQUIRED while the schema does not enforce this, but the added detail still outweighs that.

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 opens with a specific action — 'Screen Indian stocks by technical indicators' — and names the resource (real-time Indian stock data). It explicitly lists indicator families (RSI, MACD, moving averages, crossovers, volume, momentum) and distinguishes itself from screen_stocks, making the tool’s scope unmistakable.

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?

It provides an explicit routing rule: for fundamental screening (PE, ROCE, Sales, Growth), use screen_stocks instead. This directly answers when to use this tool versus its sibling, going beyond implied usage to a clear directive with an example.

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