Inspect a data file

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds useful output behavior (a preview plus per-column stats), but it contradicts the schema on supported formats by listing JSON as a valid input when the file parameter explicitly excludes JSON/BSON - a misleading claim an agent could act on.

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?

Two sentences with zero waste: the first front-loads what is returned, the second front-loads when to call it. Nothing redundant with title or schema.

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 no output schema, the description correctly carries the return-value burden by enumerating the reported statistics and the preview size. It is nearly complete for a one-parameter read-only tool; the only gap is the conflicting statement about supported file formats.

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?

Only one parameter, and the schema documents it at 100% coverage including attachment conventions (file://, @name, #file:), relative path resolution and large-file tolerance. The description adds no parameter semantics beyond the schema, so the baseline of 3 applies.

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 verb ('Lists the columns') plus what exactly is reported: types, missing values, ranges, category values and a 5-row preview. That distinguishes it from siblings like describe or group_summary, though it slightly misfires on scope by naming JSON as supported when the schema says JSON/BSON is not supported.

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?

Gives a concrete when-to-use: 'before running tests on a file so you pass correct column and group names', which ties it to run_test/choose_test in the sibling list. It offers no exclusions or alternatives for cases where a full profiling tool (describe) would be a better fit.

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