preview_obs

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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions 'preview' hinting at a read operation, but does not specify side effects, permissions, rate limits, or what happens to data. Lacks explicit behavioral details.

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 very short (one phrase), which is concise but omits essential information. It is appropriately sized for a quick overview but could benefit from a few more details.

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?

Given the complex input schema with nested objects and no output schema, the description is severely incomplete. It does not define 'obs', explain the output format, or elaborate on cardinality, leaving agents uninformed.

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 'slice' and 'cardinality', loosely relating to filters and limit parameters, but does not clarify their meaning or usage. With 0% schema description coverage, the description fails to compensate adequately.

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 'Small obs slice + column cardinality (before a big scan)' conveys the tool's purpose as a preview tool for a small slice of observations and column cardinality, distinguishing it from siblings like count_cells or gene_coverage. However, it relies on domain jargon and could be more explicit.

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 phrase 'before a big scan' implies usage for quick checks prior to larger operations, but no explicit when-to-use or when-not-to-use guidance is provided, nor are alternatives mentioned.

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