MCP Datadog Server

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

No annotations are provided, so the description carries full burden. It states 'Get' implying a read operation, but doesn't disclose behavioral traits such as authentication needs, rate limits, whether it returns a single metric or details, error conditions, or if it's idempotent. For a tool with zero annotation coverage, this leaves significant gaps in understanding how it behaves.

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 sentence: 'Get a specific span-based metric from your organization.' It's front-loaded with the core action and resource, with no wasted words. However, it could be slightly more informative (e.g., clarifying 'specific' or adding context), but it's efficient and to the point.

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 has no parameters, no annotations, and no output schema, the description is incomplete. It doesn't explain what 'specific' means (e.g., by ID or name), what a 'span-based metric' entails, the return format, or error handling. For a tool that likely retrieves configuration data, more context is needed to use it effectively without trial and error.

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 tool has 0 parameters with 100% schema description coverage (empty schema), so no parameter documentation is needed. The description doesn't add param info, but that's acceptable as there are no parameters to explain. Baseline is 4 for 0 params, as the description doesn't need to compensate for any gaps.

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 'Get a specific span-based metric from your organization', which provides a verb ('Get') and resource ('span-based metric'), but it's vague about what 'specific' means and doesn't differentiate from sibling tools like 'get_apm_config_metrics' (plural) or 'aggregate_spans_analytics'. It clarifies it's for APM configuration metrics, but lacks specificity on scope or selection criteria.

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?

No guidance is provided on when to use this tool versus alternatives. The description doesn't mention prerequisites, context (e.g., after creating metrics), or comparisons to siblings like 'get_apm_config_metrics' (which might list multiple) or 'aggregate_spans_analytics' (which might aggregate data). Usage is implied only by the tool name, with no explicit when/when-not instructions.

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