AWS MCP Server

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

Without annotations or output schema, the description carries the full transparency burden. It partially compensates by enumerating return fields (status, logs, duration, phases), giving insight into what data is retrieved. However, it omits error handling (invalid IDs), required IAM permissions, and 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 of nine words with front-loaded verb. Highly efficient with no redundancy. However, the brevity comes at the cost of missing behavioral and contextual details that would be valuable given the lack of annotations.

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 tool with no annotations and no output schema, the description provides the essential return field information (status, logs, duration, phases) which is necessary for utility. However, it lacks usage context, permission requirements, and error behavior that would make it complete for an AWS API 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%, providing clear documentation for all parameters (profile, region, ids). The description adds minimal parameter-specific semantics beyond the schema, though it implicitly contextualizes 'ids' as referring to CodeBuild builds through the resource mention.

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?

Specific verb 'Get' and resource 'CodeBuild builds' with clear scope of return data (status, logs, duration, phases). Implicitly distinguishes from sibling 'list_builds_for_project' by targeting specific builds by ID vs listing, though it could explicitly clarify the 'batch' capability implied by the tool name.

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?

Specifies what the tool retrieves but provides no explicit guidance on when to use it versus siblings like 'aws_codebuild_list_builds_for_project' or 'aws_codebuild_batch_get_projects'. No mention of the typical workflow (e.g., that you need build IDs from elsewhere first).

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