MCP Datadog Server

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

With no annotations provided, the description carries full burden and adds valuable behavioral context: it specifies maximum payload size (500KB), compressed payload limits (decompressed <5MB), and detailed byte expectations for timestamp, value, metric names, and timeseries. It also mentions host name as a resource field. This goes beyond basic functionality to include important constraints and implementation details.

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 moderately concise but could be better structured. The first sentence clearly states the purpose, but subsequent technical details about payload sizes and byte expectations are presented as separate facts without clear organization. Some information (like the 100-byte approximation) feels extraneous rather than essential for tool selection.

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 complexity (data submission with specific constraints), no annotations, and no output schema, the description provides substantial context about behavioral constraints and technical requirements. It covers payload limits, data format expectations, and resource considerations. While it doesn't explain return values (no output schema exists), it gives enough information for an agent to understand the tool's operation and limitations.

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 0 parameters with 100% coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, instead focusing on payload characteristics and constraints. This meets the baseline expectation for a tool with no parameters.

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 the tool posts time-series data to Datadog's metrics endpoint for graphing on dashboards, which clarifies the verb ('post') and resource ('time-series data'). However, it doesn't distinguish this from sibling tools like 'submit_distribution_points' or 'metrics_submit_series' that appear to have similar functions, leaving the purpose somewhat vague regarding differentiation.

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 explicit guidance on when to use this tool versus alternatives. It mentions submitting metrics directly to the API without DogStatsD, but doesn't specify when this approach is preferred or what alternatives exist among the many sibling tools. There's no 'when-not' or clear contextual usage advice.

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