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

Annotations already cover readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety profile is clear. The description adds that a suggested formula may be returned, which is useful. But with an output schema present, much of the return behavior is structured elsewhere, so the add is modest.

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 tight sentence, front-loaded with the action, followed by illustrative operation types and the return hint. No filler.

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 annotations and an output schema covering return shape, the description is nearly complete for a 2-param read tool. Only missing explicit sibling routing for query_document/query_ledger, which would make it fully self-sufficient.

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 descriptions and examples for both params. The description restates that a question is being answered, which adds little beyond the schema's own example ('total revenue in Q3'). Baseline 3 is appropriate when the schema does the heavy lifting.

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+resource: 'Answer a question or compute a result over one of the user's Xenition spreadsheets', with concrete operation types (sums, trends, lookups). The mention of 'spreadsheets' distinguishes it from query_document, query_ledger, and ask_workspace.

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?

Implied usage ('over one of the user's Xenition spreadsheets') but no explicit when-to-use vs alternatives like query_document, query_ledger, or summarize_artifact. Agent must infer spreadsheet-specific routing from the resource name alone.

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