get_sector_briefing

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

Annotations already declare readOnlyHint and idempotentHint. The description adds important context: PER/ROE exclude net-loss stocks, PBR excludes negative-book stocks, and margin_ratio fields are null unless cache is populated. No contradiction.

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?

Well-structured: purpose first, then usage, exclusions, alternatives, plan-specific notes, and parameter details. Every sentence adds value with 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?

Given the output schema exists, the description covers all necessary aspects: purpose, usage, behavioral caveats, parameter explanation, and plan limitations. It is complete for a single-parameter tool with rich annotations.

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 input schema has only 'sector_type' with no description. The description clarifies it accepts 's33' (33 sub-sectors) or 's17' (17 sectors), adding meaning beyond the schema.

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 states it returns sector-level median PER, PBR, ROE, and margin ratio, which is a specific verb+resource. It also lists sibling tools to distinguish itself.

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?

Explicitly provides use cases (e.g., 'sector valuation, sector PER/PBR, cheap sectors') and recommends alternative tools like get_market_briefing and get_stock_briefing.

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