suggest_gsi

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

With no annotations, the description fully carries the burden. It discloses that the tool generates a definition (read operation), does not verify existing GSIs, and implies no side effects. This is transparent and adds value beyond structured fields.

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 front-loaded information: first sentence defines the tool, second sentence gives usage context, third sentence covers a key limitation. No redundant words, every sentence earns its place.

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?

Despite no output schema, the description adequately describes the output structure. It integrates well with sibling tools by referencing get_infra_overview. All behavioral aspects are covered for a two-parameter 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 coverage is 100%, so the description adds minimal value beyond the schema descriptions. It restates 'attribute' as the attribute to create the GSI on, which is already clear from the schema. Baseline 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 it generates a DynamoDB GSI definition, specifying the output components (index name, partition key, projection type, billing mode) and the context (for a given table and attribute). It is distinct from sibling tools that handle other index types or infrastructure overview, ensuring unambiguous purpose.

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: when a query pattern needs a missing index or when the analyzer flags a missing GSI finding. Also provides a when-not-to-use: it does not verify existence, and directs the agent to check table schema via get_infra_overview first, offering a clear alternative.

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