extract_fields

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds valuable context beyond the schema by specifying the tab-separated output format, one packet per line, and the use of a keylog file for TLS decryption with example fields. It does not explicitly state read-only behavior, but this is strongly implied by the extraction nature and the provided examples.

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 well-structured with a summary, Args, and Returns sections. Every sentence contributes meaningful information, and there is no redundant or filler content. The length is appropriate for the tool's complexity.

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 covers the tool's purpose, all parameters, return format, and decryption capability, making it largely complete for the given complexity. However, it lacks any mention of when to use this tool relative to siblings or potential limitations (e.g., handling very large files), which prevents a perfect score.

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 schema has 0% description coverage, but the description compensates thoroughly. Each parameter is explained in the Args section: file_path (path to PCAP), fields (comma-separated, with examples), display_filter (optional), and keylog_file (optional, for TLS decryption). It also clarifies the expected field syntax and decryption usage, adding meaning far beyond the bare schema.

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 with a specific verb ('Extract') and resource ('packets in a PCAP file'), and adds the qualifier 'specific fields' which distinguishes it from broader tools like extract_packet_details or export_to_json. This makes the intent unambiguous.

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?

There is no guidance on when to use this tool versus sibling tools such as filter_and_save or extract_packet_details. The description explains how to invoke the tool but not the context in which it is preferred over alternatives, nor any exclusions.

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