inspect_file

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

With no annotations, the description fully discloses behavior: it 'makes no API call', 'reads from cached graph.json', and the count is 'not live' and should be treated as an 'order-of-magnitude hint'. This reveals staleness and performance characteristics beyond what annotations would provide, ensuring the agent understands the tool's limitations.

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 concise, front-loaded with the primary purpose, and every sentence earns its place: it covers the output, the caveat about non-live counts, the performance characteristic (INSTANT), and a usage example. No fluff or 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 description provides rich behavioral context (caching, staleness, speed) and usage guidance, and an output schema exists to detail return values. However, the folder_path parameter is not explained, and the description does not mention potential error cases or prerequisites. These gaps are minor given the tool's simplicity.

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 explain parameters. It implicitly covers file_name via 'one specific file', but it does not mention folder_path at all. This leaves one of two parameters unexplained, which is a significant gap in parameter semantics.

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 clearly states the tool's purpose: 'Returns structural metadata for one specific file — sheet names, column headers, and each sheet's approx_row_count.' This is specific with a verb ('returns') and resource ('one specific file'), and it distinguishes the tool from siblings by emphasizing structural metadata and its use before filter_sheet.

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 explicitly advises 'Use before filter_sheet when you need to confirm the exact column names available in a specific file.' This provides a clear when-to-use scenario and a named alternative. It also notes that the tool makes no API call, implying it is for quick checks rather than live operations.

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