Last quote

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

Description adds context beyond annotations: 'read live from the engine and never cached' and 'Returns structuredContent alongside the text.' This covers caching behavior and output format, aligning with readOnlyHint and openWorldHint.

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 concise sentences, front-loaded with purpose. No wasted text, efficiently conveys all necessary information.

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 high schema coverage, output schema presence, and annotations covering read-only and open-world aspects, the description is complete. It specifies live, uncached data and return structure, sufficient for agent understanding.

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 parameters. The description adds no new meaning beyond what the schema already provides, meeting baseline but not exceeding.

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?

Clearly states it provides top-of-book quote (best bid/ask and sizes) for a symbol on a venue. Distinctly differentiates from sibling last_trade by noting that tool is for last traded price.

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 tells the agent when not to use this tool (for last traded price) and directs to the alternative last_trade. Also implies live, uncached nature guides appropriate use.

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