get_market_holidays

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

The annotations provide readOnlyHint=true, indicating this is a safe read operation. The description adds context about what data is retrieved ('upcoming market holidays' and 'open/close times'), which is useful beyond the annotation. However, it doesn't disclose other behavioral traits like rate limits, authentication requirements, or data freshness that would be helpful for an agent.

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 extremely concise with just one sentence that clearly states the tool's purpose. Every word earns its place, and there's no wasted language or unnecessary elaboration. It's front-loaded with the core functionality.

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 tool's simple purpose (retrieving holiday data), the presence of annotations (readOnlyHint), and an output schema (which handles return values), the description is reasonably complete. It clearly states what data is retrieved. The main gap is lack of usage guidance relative to sibling tools, but for a straightforward read operation, this is acceptable.

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 1 parameter with 0% description coverage, and the tool description provides no parameter information. However, since the parameter appears optional (default: null) and the tool likely functions without it (based on the description's focus on 'upcoming' holidays), the baseline of 3 is appropriate. The description doesn't add parameter semantics but doesn't need to compensate heavily given the simple parameter structure.

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 clearly states the tool's purpose: 'Get upcoming market holidays and their open/close times.' It specifies the verb ('Get') and resource ('market holidays') with additional detail about what information is included ('open/close times'). However, it doesn't explicitly differentiate from sibling tools like 'get_market_status' which might provide related information, keeping it from a perfect score.

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 no guidance on when to use this tool versus alternatives. With many sibling tools available (e.g., 'get_market_status', 'list_futures_schedules'), there's no indication of when this specific tool is appropriate or what distinguishes it from others that might provide market-related data.

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