AWS MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While 'List' implies read-only, it doesn't explicitly confirm safety, describe pagination behavior for large vault lists, explain rate limiting, or indicate whether deleted vaults are included in results.

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 and appropriately brief, but underspecified rather than elegantly concise. Every word technically earns its place in terms of space used, but the sentence as a whole provides minimal value beyond the tool name itself.

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 complexity of AWS Backup service and presence of multiple sibling backup tools, the description is insufficient. It doesn't explain what a backup vault is, what information is returned, or how vaults relate to backup plans and recovery points. With no output schema, the description should compensate but doesn't.

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% for all three parameters (profile, region, max_results). The description adds no semantic information beyond the schema, but baseline 3 is appropriate when the schema fully documents parameters. The description doesn't explain parameter relationships (e.g., that region is required if not in profile).

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 'List AWS Backup vaults' is a tautology that restates the snake_case tool name. It identifies the resource (AWS Backup vaults) but fails to distinguish from siblings like aws_backup_list_recovery_points_by_backup_vault or aws_backup_list_backup_jobs, which operate on different backup entities.

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 provided on when to use this tool versus alternatives (e.g., when to list vaults vs listing recovery points within them). No mention of prerequisites, AWS authentication requirements, or that vaults are regional resources requiring the region parameter.

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