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

The description adds meaningful behavioral context beyond annotations: it fetches the URL, inspects Set-Cookie headers, and flags specific insecure patterns. It also reveals the scoring model (weakest cookie, not average) and that average_score is separate. This adds value beyond the readOnlyHint and destructiveHint annotations, though it does not discuss potential side effects like redirects or network latency.

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 a compact, information-dense paragraph with a clear front-loaded purpose. It lists checked attributes and flag conditions without fluff, and every sentence adds value. The scoring explanation is valuable and not redundant.

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?

Despite having an output schema, the description explains the return values (per-cookie grades, overall score, average_score) and the scoring semantics. It covers the tool's behavior sufficiently for an agent to select and invoke it correctly, including edge cases like SameSite=None without Secure. No significant gaps remain.

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 already provides 100% coverage for the single 'url' parameter with a clear description and example. The tool description adds 'any URL' and clarifies what the URL is used for, but this is marginal. Given the high schema coverage, a baseline of 3 is appropriate.

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 begins with a specific verb+resource: 'Audit the security attributes of cookies set by any URL.' It clearly distinguishes from siblings like security_headers_check and web_security_audit by focusing exclusively on cookie attributes and set-cookie behavior. The list of inspected attributes and flagged patterns further specifies the tool's exact scope.

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 provides clear context for when to use the tool: it audits cookies from any URL and lists specific security checks. However, it does not explicitly name alternatives or state when not to use this tool, even though siblings like security_headers_check and web_security_audit overlap somewhat. The context is clear but exclusions are absent.

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