Open a page

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

Goes well beyond the annotations (which only flag openWorld/idempotent/non-destructive) by disclosing that logins persist in a dedicated profile, that the action is recorded as a goto step in a task, that the page may be truncated, and that snapshot text is untrusted data whose instructions must never be followed. These are material behavioral facts an agent cannot infer from structured fields.

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?

Front-loads the core action and return value, then appends only operationally necessary caveats (login handoff, untrusted snapshot) in short clauses. No filler or restatement of the title.

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?

With no output schema, the description still explains what is returned (accessibility snapshot with ref ids), how it is consumed (browser_act), and the safety posture of the returned content. Nothing an agent needs to invoke this correctly appears missing.

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 coverage is 50%: maxChars is documented in the schema, url is not. The description constrains the url to http(s), which is real added meaning, but it never mentions maxChars or the truncation cap parameter beyond the general snapshot note. Baseline 3 is appropriate given the partial coverage.

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?

States a specific verb and resource ('Opens an http(s) URL in Ritoko's Chrome') and disambiguates from siblings by naming the return artifact and its consumer ('accessibility snapshot with [ref=…] ids for browser_act'). An agent can tell this apart from browser_snapshot and browser_act without opening a schema.

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?

Gives concrete context for use (dedicated profile with persisting logins, records a goto step) and explicit handling for blocked flows ('On a login, MFA or CAPTCHA page, ask the user to complete it in that window'). It routes the snapshot refs to browser_act, but does not explicitly state when to prefer browser_open over browser_snapshot or how it fits the workflow/run siblings.

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