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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered externally. The description adds essentially nothing beyond that: it does not say what the data argument is, how the column reference resolves when both a name and an index are valid, or how results are returned.

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?

A single compact sentence that front-loads the operation set and tucks the column-reference detail into a parenthetical. No filler, though the abbreviation style is terse to the point of losing clarity.

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 fairly simple single-column aggregation tool this is minimally adequate, and annotations cover the safety profile. However, with no output schema and 0% parameter coverage, the description leaves the primary required input ('data') and the result shape unexplained.

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 0%, so the description must carry the full parameter burden. It usefully enumerates the op values and explains that column accepts a name or 0-based index, but it never explains the required 'data' parameter or the 'format' parameter, leaving half the schema undocumented.

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?

States a specific operation set (sum/avg/min/max/count/distinct) and the resource it acts on (one column), so an agent can identify it as a column-aggregation tool immediately. It does not name or differentiate itself from siblings clean_table, convert_table, or split_column, but those are clearly different operation types so confusion is unlikely.

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 gives no when-to-use guidance, no prerequisites, and no mention of alternatives. Usage is only inferable from the operation list itself.

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