bulk_default

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

With no annotations present, the description carries the full burden. It discloses the return shape, fields, direct-fetch requirement for jsonl_download_uri, and the gzipped JSONL format with one card per line. This is substantive behavioral detail, though it omits potential details like rate limits or auth requirements.

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?

The description is compact and front-loaded: primary purpose first, then response structure, then payload format, then intended use. Every sentence adds useful information without repetition or fluff.

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 zero-parameter tool with no output schema, the description is thorough: it explains what the tool returns, what the fields represent, how to obtain the actual data, the file format, and why an agent would use it. No critical information for correct invocation appears 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?

The tool has zero parameters and 100% schema coverage, so there is nothing parameter-related for the description to explain. Per the baseline for 0-parameter tools, a 4 is appropriate because the schemas and description together leave no parameter ambiguity.

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 specific verb and resource: 'List Scryfall bulk-data endpoints.' It clearly distinguishes itself from the card lookup siblings by describing a bulk-data listing capability rather than individual card queries.

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 statement 'Useful for offline corpus building' provides clear context for when to choose this tool. It does not explicitly name sibling alternatives or state when-not-to-use, but the bulk-data framing makes the intended use obvious.

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