binary.data_vars

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

With no annotations, the description carries the full burden of behavioral disclosure, but it only states the action and pagination. It doesn't mention whether this is read-only, what data variables are, how pagination behaves (e.g., ordering, total count), or any session requirements beyond the schema. The term 'List' implies a safe read, but that's implicit.

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 a single, focused sentence with no unnecessary words, making it concise and front-loaded.

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 simple list operation with a required session parameter and pagination, the description is minimally adequate but incomplete. It lacks any context about what data variables are, what session_id refers to, and what the return format is (though no output schema exists). The agent can invoke it correctly with session_id, but lacks broader context.

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 description mentions 'pagination,' which loosely maps to limit and offset, but provides no explanation of session_id or the pagination semantics. With 0% schema description coverage, the description should compensate, but it only hints at one concept.

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 uses the specific verb 'List' with the resource 'data variables' and notes pagination. It clearly conveys the primary action, but doesn't explicitly differentiate from sibling list operations like binary.functions or binary.strings, relying instead on the resource name.

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 description offers no guidance on when to use this tool versus alternatives. There are no exclusions, prerequisites, or alternative tool references, leaving the agent to guess based on naming.

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