describe_source

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

No annotations are provided, so the description carries the burden. It discloses that output size is small and that sample rows are capped at the requested value (default 5), which is useful. However, it does not mention error conditions (e.g., what happens if source_id does not exist) or any other side effects, leaving some behavioral gaps.

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 two sentences, front-loaded with the core purpose, and includes only essential operational details (output size, cap). Every sentence earns its place with no redundancy.

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?

The tool has a simple purpose and an output schema exists, so the description need not enumerate return fields. It covers the key aspects: what is returned, sample row cap, and output size. Minor gaps include lack of explicit prerequisites beyond 'loaded source' and no mention of error behavior, but given the output schema and simplicity, it is mostly complete.

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?

Schema description coverage is 0%, so the description must compensate. It explicitly explains 'sample_rows' by describing the cap and default value, which adds meaning beyond the schema. It does not explicitly name 'source_id', but the phrase 'loaded source' implies it; still, it could be more explicit about how source_id is used.

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 a specific verb 'Return' and clearly states the resource ('a loaded source') and the exact contents of the return (schema, sample rows, footprint). This distinguishes it from siblings like sample_rows or profile, which focus on subsets.

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 gives clear context that this is for loaded sources and returns descriptive metadata, which implies a use case. However, it does not explicitly contrast with alternatives like 'sample_rows' or 'profile', so it lacks explicit when-not-to-use guidance.

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