Get hidden gems

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

Annotations already declare readOnlyHint, so no additional safety context needed. The description adds value by disclosing the return shape (`{gems:[...], totalCount, lastScanAt}`) and explaining the freshness filter's semantics, which enriches the agent's understanding 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?

Two sentences, no filler. The first sentence defines the tool's purpose with concrete criteria; the second covers return format and usage. Every sentence earns its place.

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 read-only list tool with two optional parameters and no output schema, the description covers the essential context: purpose, screen definition, freshness meaning, and return structure. It could add more about the shape of each gem, but the total context is sufficient for selection and basic invocation.

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 description coverage is 100%, so both parameters are already documented. The description rephrases the freshness parameter ("filters by how recently a gem's signals fired") but adds no new technical detail beyond what the schema provides, yielding a baseline score.

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 returns undervalued small-caps with confirming signals, specifying the 'hidden gem' screen criteria. This distinguishes it from sibling tools like momentum-focused screens, fulfilling a specific verb+resource+scope.

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 clear usage context by recommending it for value-oriented idea generation and explicitly contrasting it with momentum. It does not name alternative tools or provide explicit when-not-to-use, but the context is strong enough.

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