stock-moves-explained

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral context: output is AI-written analysis, coverage is 550+ stocks across major indices, and it explicitly excludes predictions and other financial services. No contradiction with 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 compact and front-loaded. The first sentence states the core purpose, followed by one sentence on output characteristics, one on coverage, and one on exclusions/alternatives. Every sentence earns its place with no redundancy or fluff.

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 tool with annotations and full schema coverage, the description sufficiently covers purpose, scope, exclusions, and even an access fallback. It lacks details about return format or what counts as 'significant,' but no output schema exists and these are not critical for an agent to invoke the tool 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?

The input schema covers 100% of parameters with detailed descriptions, including examples for ticker and format for date. The description reinforces 'Pass any stock ticker or company name as the ticker parameter' but adds no new semantic information beyond what the schema already provides. Baseline of 3 applies due to full schema coverage.

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 and resource: 'Explains why a stock had a significant price move today.' It further clarifies the output type (AI-written analysis citing news catalysts, earnings reports, and analyst actions) and coverage (S&P 500, NASDAQ 100, Dow 30), making the tool's purpose unmistakable and distinct from generic quote or prediction tools.

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?

The description provides clear exclusions: 'NOT for: price quotes, trading advice, predictions, crypto, or forex.' It also mentions an alternative access method when POST requests are unavailable. However, it does not name alternative tools to use instead, though the sibling list is empty, so this is a minor gap.

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