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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the 'real-time' context and expected output fields, but does not disclose potential latency, rate limits, or API key expiration considerations.

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 a single focused sentence followed by a helpful example. There is no filler, and the key purpose and expected outputs are front-loaded.

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 simple read-only tool with complete parameter schemas, annotations, and an output schema, the description is sufficient. It could be improved by noting whether quotes are delayed or unavailable during market closures, but this is a minor gap.

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 coverage is 100% with clear descriptions for both symbol and _apiKey. The description's example adds a concrete call format but does not meaningfully explain the parameters beyond what the schema already provides, so the baseline 3 applies.

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 a specific operation—retrieving a real-time stock quote—and lists concrete return fields: current price, change, and volume. This clearly distinguishes it from sibling tools like get_company_news or get_earnings_calendar.

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 implies use when a current stock quote is needed, and the example shows a valid invocation. However, it does not explicitly mention when not to use this tool or point to alternatives such as search_symbol for finding tickers first.

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