profile_file

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

With no annotations, the description carries the burden and does disclose real behavioral traits: full-file scan cost, risk of hitting the time limit on very large files, and the default 50-column cap. It does not state permissions/side-effect profile or that the distinct count is an estimate beyond the parameter naming, leaving a modest gap.

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?

Front-loaded with the output contract, then usage, then a performance caveat — three sentences, each carrying distinct information. No filler or repetition.

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 an output schema present, the description needn't restate return values, and the column-limit behavior plus the timeout caveat cover the main invocation risks. Minor omissions: supported file formats/locations and whether the scan is read-only are not stated, but nothing critical to calling it correctly is missing.

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 compensate, and it does for the non-obvious parameter: `columns` restricts profiling to named columns, otherwise the first 50 are used. `path` is left unexplained but is self-evident for a file-profiling tool. Low param count keeps the residual gap small.

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 opens with a precise verb+resource ('Profile each column of a file in one pass') and enumerates exactly what is computed: type, null %, approximate distinct count, min, max, average, median, top three values. That is far more specific than a title restatement. It lacks an explicit contrast with siblings like describe_file or sample_file, so it falls short of the top band.

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?

'Use it to spot data-quality problems (many nulls, constant columns, odd ranges) before analysing' gives a clear triggering context. The large-file caveat with the fallback ('profile fewer columns') adds actionable guidance. No explicit when-not or named alternative is given, which keeps it out of the 5 band.

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