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Preview rows

preview_data
Read-only

Preview the first N rows of a local data file as a Markdown table to quickly inspect its contents before deeper analysis.

Instructions

Return the first N rows of a local data file as a Markdown table.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
pathYesPath to the data file.
limitNoRows to show (default 20).
offsetNo
Behavior3/5

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

Annotations already declare readOnlyHint=true, and the description adds that the operation is local and returns a Markdown table. It does not disclose offset behavior, behavior on missing files, or whether large files are fully loaded, but for a simple read-only preview the annotations and description together are adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single front-loaded sentence with no filler. Every phrase contributes meaning: return, first N rows, local data file, Markdown table.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description explains the return format and core operation, but it omits offset semantics and does not position the tool relative to the sibling tools. Since there is no output schema, a bit more context about edge cases or usage would improve completeness.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema documents path and limit, but offset lacks a description. The phrase 'first N rows' adds little beyond the schema's 'Rows to show (default 20)', and no parameter-level meaning is added in the description for offset.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action ('Return'), the resource ('first N rows of a local data file'), and the output format ('Markdown table'). This is specific enough to distinguish it from siblings like query_data, which implies a more general row-returning operation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives no guidance about when to use this tool versus alternatives such as query_data or describe_data, and it does not state exclusions or prerequisites. The use case is only implied by the word 'preview' in the title and 'first N rows' in the description.

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

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