Databento MCP

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the action ('Clear') which implies a destructive operation, but doesn't specify whether this requires special permissions, affects system performance, has rate limits, or what happens after execution (e.g., cache repopulation). For a potentially destructive tool with zero annotation coverage, this is inadequate.

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 that communicates the core purpose without any wasted words. It's appropriately sized for a simple tool and gets straight to the point with efficient language.

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 potentially destructive cache-clearing operation with no annotations and no output schema, the description is insufficient. It doesn't explain what 'clearing' entails, potential side effects, or what confirmation/response to expect. Given the tool's nature and lack of structured metadata, more contextual information would be valuable.

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 description doesn't mention any parameters, but the input schema has 100% description coverage for its single parameter 'expired_only'. The schema already documents this parameter well with a clear description and default value, so the description doesn't need to compensate. This meets the baseline expectation when schema coverage is high.

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 action ('Clear') and the target resource ('API response cache'), making the purpose immediately understandable. However, it doesn't differentiate this tool from its siblings, as none of the other tools appear to be cache-related operations, so this isn't a major deficiency.

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, prerequisites, or typical scenarios. It doesn't mention whether this should be used for performance troubleshooting, data freshness issues, or other contexts, leaving the agent with minimal usage context.

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