Aard

Fallback: stage an Aard-issued dataset

stage_url

Fallback for clients that cannot download and query the source locally.

Use only when local execution is unavailable or the user explicitly asks for Aard-managed staging. Never fetch the URL with web search or request its response body directly. Stage the exact unchanged fallback URL outside model context; this tool returns metadata only. Use its dataset_id with inspect_dataset or query_dataset.

The URL alone is sufficient. download_ref is an optional fast path — if you cannot copy it exactly, OMIT it rather than risk mistyping it; the server then re-derives the grant itself and the call still succeeds.

no_records_for_selection is TERMINAL, not a fault: the request was well-formed and the source holds no observations for it. Widen the selection or state that no data exists — do not retry the same selection.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes	The exact csv_url/download_url from build_url, byte-for-byte. This is the value that matters — an edited URL is refused.
`format`	No	Content-type handling. "auto" (default) requires the origin to declare a CSV media type. "csv" and "sdmx-csv" additionally accept an application/octet-stream response, for origins that serve CSV without labelling it — use them only when "auto" fails with unsupported_content_type.	auto
`download_ref`	No	Optional. The signed grant from the same build_url result, copied exactly. Omit it if you cannot.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`sha256`	Yes
`dataset_id`	Yes
`expires_at`	Yes
`content_type`	Yes
`bytes_downloaded`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedSep 28, 2026

addedInput schema / properties / download_ref / description

Added value: +"Optional. The signed grant from the same build_url result,\ncopied exactly. Omit it if you cannot."

addedInput schema / properties / format / description

Added value: +"Content-type handling. \"auto\" (default) requires the origin to\ndeclare a CSV media type. \"csv\" and \"sdmx-csv\" additionally accept\nan application/octet-stream response, for origins that serve CSV\nwithout labelling it — use them only when \"auto\" fails with\nunsupported_content_type."

addedInput schema / properties / url / description

Added value: +"The exact csv_url/download_url from build_url, byte-for-byte. This\nis the value that matters — an edited URL is refused."

First observedSep 15, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations cover the safety profile (readOnly=false, openWorld=true, non-idempotent, non-destructive), and the description adds substantial behavior beyond them: metadata-only return, URL-alone sufficiency, the optional/omittable download_ref with server-side grant re-derivation, and the terminal semantics of no_records_for_selection. This is exactly the extra context annotations cannot carry.

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

Conciseness4/5

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

Front-loads the fallback framing, then layers usage constraints, parameter guidance, and the terminal-error note. It is on the longer side, but each paragraph earns its place; only minor compression is possible.

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

Completeness5/5

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

With an output schema present, return values need not be described, and the description instead covers prerequisites, the local-vs-staged decision, exact-copy requirements, and the non-retryable terminal error. Nothing an agent needs to call this correctly is missing.

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

Parameters4/5

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

Schema coverage is 100%, so the baseline is 3, but the description adds decision-level guidance: the URL alone is sufficient, and download_ref should be omitted rather than mistyped since the server re-derives the grant. That meaningfully reduces the risk of a failed call, though the format enum handling is left to the schema.

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?

States a specific verb (stage) and resource (an Aard-issued fallback dataset URL), and frames it as a fallback that returns metadata only. It distinguishes itself from the siblings it hands off to (inspect_dataset, query_dataset), so an agent can place it in the workflow without opening any schema.

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

Usage Guidelines5/5

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

Gives explicit when-to-use ('only when local execution is unavailable or the user explicitly asks for Aard-managed staging') and when-not ('Never fetch the URL with web search or request its response body directly'). It also names the downstream alternatives and how to proceed from the returned dataset_id, leaving nothing to inference.

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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