AWS MCP Server

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

No annotations provided, so description carries full burden. 'Describe' implies read-only but doesn't confirm non-destructive behavior or idempotency. Fails to disclose what happens when db_cluster_identifier is omitted (returns all clusters vs error) or mention pagination/rate limits.

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?

Single sentence with no filler words. Every word earns its place identifying the service and resource. However, given zero annotations and multiple sibling tools with similar names, the description is arguably too brief rather than appropriately concise.

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?

With no annotations, no output schema, and 3 parameters, the description should provide more context. It fails to explain that omitting db_cluster_identifier returns all clusters, doesn't clarify AWS credential requirements, and doesn't distinguish DocumentDB vs Aurora behavior despite having a DocumentDB sibling tool.

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 100%, so baseline is 3. The description mentions 'clusters' which loosely maps to the db_cluster_identifier parameter but adds no syntax details, validation rules, or format examples beyond what the schema already provides.

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 uses specific verb 'Describe' and resource 'RDS Aurora database clusters', distinguishing from siblings like aws_docdb_describe_db_clusters (DocumentDB), aws_memorydb_describe_clusters (MemoryDB), and aws_rds_describe_db_instances (instances vs clusters). However, it doesn't explicitly state this is a read-only operation.

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?

Provides no guidance on when to use this tool versus similar siblings (e.g., when to use describe_db_clusters vs describe_db_instances for Aurora Serverless v2 provisioned instances). No mention of prerequisites like AWS profile requirements.

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