Ensure Index

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

Annotations declare idempotentHint=true and openWorldHint=false. The description complements by explaining the build/refresh process and the return value. It does not contradict annotations and adds context about the index state. However, it could mention potential side effects like disk usage or time consumption.

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 that is front-loaded with the action and outcome. Every word is necessary, and it avoids redundancy.

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 tool's complexity (6 optional parameters, output schema exists), the description covers the core purpose and return value. However, it lacks context on when to use parameters like forceRebuild vs refreshOverlay, and could mention performance implications. The annotation partially compensates.

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 each parameter is documented in the schema. The tool description does not add extra meaning beyond what the schema provides. The baseline for high coverage is 3.

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 verb 'Build or refresh' and the resource 'local regex index', and specifies the output 'return the active base revision plus overlay state'. This distinguishes it from sibling tools like index.status (status check) and search.* (search operations).

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?

The description implies when to use the tool (when an index needs to be built or refreshed) but does not provide explicit guidance on when not to use it or alternatives. There is no mention of prerequisites or comparison with sibling tools like index.status or index.clear.

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