suggest_gsi

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

With no annotations, the description carries full burden. It discloses a key limitation (does not verify existence) but does not mention if the operation has side effects or requires permissions. Some transparency is provided, but incomplete.

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?

Three sentences with no wasted words. First sentence defines purpose, second gives usage context, third adds critical caveat. Well structured and front-loaded.

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 simple tool with 2 string parameters and no output schema, the description covers purpose, when to use, and a limitation. It references a sibling for additional context. Minor omission: output format not described, but overall sufficient for its complexity.

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 coverage is 100% with clear parameter descriptions. The description adds no additional parameter-level meaning beyond restating 'given table and attribute'. Baseline score of 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?

The description clearly states the tool generates a DynamoDB GSI definition with specific components (index name, partition key, projection type, billing mode). This distinguishes it from sibling tools like suggest_mongo_index or mysql_index_suggestions.

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?

Explicitly states when to use (query pattern needs index or analyzer flags missing GSI) and when not to (GSI may already exist; advises to check via get_infra_overview first). This provides clear guidance and references a sibling tool for prerequisite action.

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