Get active connection count

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds the API endpoint (GET /metrics/active-connections) but does not cover other behavioral aspects like authentication requirements, rate limits, or response format.

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 compact with two sentences: one stating the purpose and the second providing the API endpoint. No redundant or verbose 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 read-only metric retrieval tool with good annotations and full schema coverage, the description is largely sufficient. It lacks information about the return shape (since no output schema) but the task is simple enough. Minor gaps like default time ranges are documented in the schema.

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 100% coverage for all 4 parameters with descriptions and examples. The tool description does not add any additional meaning beyond what the schema provides, so baseline 3 is appropriate.

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?

Description uses specific verb 'Get' and resource 'active connection count', and clarifies it applies to Postgres or Redis instances. It distinguishes from sibling tools that retrieve other metrics (e.g., CPU, memory) or perform mutations.

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 implies usage when querying active connections for supported databases but does not explicitly state when to use this tool versus alternatives like render_get_cpu or render_get_memory. No exclusion or prerequisite information is provided.

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