ExplainTool

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

No annotations are provided, so the description carries the full burden. It only states the high-level purpose without disclosing that this is a read-only operation, what the response format is, or any prerequisites like authentication handled via parameters. The description adds minimal behavioral context beyond the obvious.

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, no wasted words. It could incorporate more context without being verbose. It is efficiently concise but lacks details that would improve utility.

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?

With 13 parameters, no output schema, and no annotations, the description is incomplete. It does not mention that it executes an OpenSearch explain API, what the expected return structure is, or any usage caveats. Much context is missing for a tool with this 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 description coverage is 85%, so the schema already documents most parameters. The description does not add any meaning beyond the schema; it does not explain that 'id' is the document ID or 'body' is the query. Baseline 3 is appropriate given high schema coverage.

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 returns information about why a document matches or doesn't match a query. It uses specific verbs ('returns information') and resource ('specific document'). However, it does not differentiate from sibling tools like SearchIndexTool, which is a related but distinct function.

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 on when to use this tool versus alternatives. It does not mention that it is for debugging scoring or that it requires an existing query. Sibling tools like SearchIndexTool have overlapping contexts, but no exclusions are provided.

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