AWS MCP Server

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

Annotations cover key behavioral traits (destructiveHint: true, readOnlyHint: false, etc.), so the description adds minimal value. It doesn't disclose additional context like potential downtime, rate limits, or auth requirements beyond what annotations imply. No contradiction with annotations exists.

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, efficient sentence with zero wasted words, clearly front-loading the core action and resource. It's appropriately sized for the tool's complexity.

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 (destructive mutation, 2 parameters with nested objects, no output schema), the description is minimal. Annotations provide safety context, but the description lacks details on behavior, outcomes, or error handling, making it adequate but with clear gaps for such a high-stakes operation.

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?

Schema description coverage is 50%, but the description adds no parameter details beyond implying 'region' and 'DB instance' as inputs. It doesn't explain what 'update' entails (e.g., which fields are modifiable) or compensate for the coverage gap, so it meets the baseline for moderate schema coverage.

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 ('Update') and resource ('RDS DB instance') with regional context ('in the given region'), making the purpose unambiguous. However, it doesn't differentiate from sibling tools like 'create-db-instance' or 'delete-db-instance' beyond the verb, which prevents 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 like 'create-db-instance' or 'delete-db-instance', nor does it mention prerequisites (e.g., existing DB instance) or exclusions. It's a basic statement without usage context.

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