stock-moves-explained

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorldHint=false, so safety is covered. The description adds meaningful context beyond that: the analysis is 'AI-written' (implying generated content), it documents the coverage universe, and it discloses a transport constraint/method with a fallback URL. It does not detail latency or rate limits, but the added behavioral context is substantial.

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 front-loaded with purpose, then coverage, then usage guidance, then exclusions, then the access fallback. Every sentence carries distinct information (analysis type, universe, exclusions, transport caveat) with no filler.

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 compensates by explaining what the analysis contains (news catalysts, earnings, analyst actions) and which instruments are covered. Combined with the exclusions and access note, an agent has everything needed to decide and call it correctly.

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%, and the schema already documents the date limit, ticker examples, and enum values for move_type, so the baseline is 3. The description's note to 'pass any stock ticker or company name as the ticker parameter' loosely reinforces the schema but adds no syntax or format detail beyond it.

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 verb+resource ('Explains why a stock had a significant price move today') and elaborates on the analysis type (news catalysts, earnings, analyst actions) and coverage universe. An agent immediately knows what the tool does and what it returns conceptually, with no ambiguity.

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 explicitly enumerates exclusions ('NOT for: price quotes, trading advice, predictions, crypto, or forex') and states the coverage scope (S&P 500, NASDAQ 100, Dow, plus portfolio stocks), giving clear boundaries. There are no siblings, so no alternative-routing is needed, and the when-not guidance is strong.

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