playwright_navigate

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

With no annotations, the description carries the full burden and does so thoroughly. It discloses that the scheme is auto-prepended, the page title is returned, all requests/responses are recorded automatically, and private/loopback addresses are rejected for SSRF protection. This goes well beyond the obvious.

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 three tightly packed sentences with no filler. The main action is front-loaded, followed by return value, recording behavior, and a security caveat with an alternative. Each sentence earns its place.

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 simple one-parameter tool, the description is remarkably complete: it explains what the tool does, what it returns, side effects (recording), security restrictions, and when to use an alternative. The existence of an output schema means return value details are covered, and the description still mentions the page title.

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?

Although schema description coverage is 0%, the description provides essential semantics for the 'url' parameter: it must be http/https, the scheme is auto-prepended, and private/loopback addresses are not allowed. This meaningfully compensates for the schema's lack of documentation.

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 function: 'Navigate the interactive session to a URL,' using a specific verb and resource. It also distinguishes itself from siblings like web_fetch by referencing the interactive session and noting differences in SSRF protection and the standalone CLI.

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 explicit usage context: it is for navigating an interactive session, and it gives a clear when-not/alternative by stating 'use the standalone CLI if you need to reach an internal/local host.' It also compares behavior with web_fetch, helping the agent understand when to choose this tool.

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