Scan HAR File for Security Issues

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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description explicitly discloses a key behavioral trait: it makes no network requests of its own and only analyzes existing traffic. It further reassures safety against any environment, including production, and lists concrete categories of issues scanned for. This is valuable context beyond the structured annotations.

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 and front-loaded: the first sentence states the core purpose, the second addresses safety and behavioral scope, and the Args section is concise. Every sentence adds useful information, with no filler or repetition beyond an acceptable parameter summary.

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 two-parameter tool with no output schema, the description is complete enough: it explains input expectations, the passive nature, and the output format options via response_format. It does not provide detailed return-value structure, but the markdown/json choices are described in the schema, and the absence of siblings reduces ambiguity.

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 input schema already fully documents both parameters, including descriptions, defaults, and enums, so the schema coverage is 100%. The description repeats the parameter names and basic types but adds little beyond what the schema already conveys, so it meets the baseline without adding substantial new meaning.

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 states a specific action ('Passively scans an existing HAR file') and a specific resource ('HAR file'), and enumerates the types of findings (security headers, cookie flags, CORS misconfiguration). It clearly distinguishes this from active scanning by emphasizing it only analyzes already-captured traffic.

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 for when the tool is appropriate: scanning HAR files typically produced by QA automation or Playwright's recordHar option. It also implies an exclusion by stating it does not send network requests, making it safe for production, though it does not explicitly enumerate alternatives or say 'use this instead of X'.

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