load_screener

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

With no annotations, the description carries the full burden. It usefully discloses the destination table, the ~729-symbol scope, and the 15-minute snapshot cadence, which is real behavioral context. But it does not say whether existing rows are overwritten, whether auth is required, or how the load is triggered, leaving notable gaps for a write-shaped loader.

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 and destination, followed by the field inventory and freshness note. No filler, no redundancy.

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 loader with an output schema, the description covers contents, destination table, and data freshness. The main missing piece is whether the load replaces or appends to table `screener`, and that gap is minor given the annotations-free, simple shape.

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 takes zero parameters, so there is nothing for the description to disambiguate beyond what the empty schema already shows. Baseline 4 applies; the field list describes data content rather than parameters, which is helpful but not strictly required.

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?

Specific verb (Load) plus resource (the full PSX screener) and destination (table `screener`), with a concrete field list that tells the agent exactly what data lands where. It does not differentiate itself from overlapping siblings such as load_fundamentals or load_prices, which cover some of the same fields, so it falls short of 5.

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?

Usage is implied: the ~729-symbol breadth and field list make it clear this is the broad market snapshot tool, and '15-min snapshot' hints at freshness expectations. However, there is no explicit when-to-use versus load_fundamentals/load_prices, and no stated prerequisites or exclusions.

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