open_browser

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

No annotations exist, so the description carries the full burden. It does disclose a genuinely behavioral fact the schema cannot convey — that a page ID is returned for later screenshots — establishing session state. However, it says nothing about browser lifecycle (must it be closed?), whether multiple browsers can be open concurrently, or resource cost, which are the main behavioral risks for a stateful tool.

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?

Two short sentences, front-loaded with the action and followed by the return value. Nothing is redundant and every clause carries information.

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 12-parameter, no-annotation, no-output-schema tool, the description does cover the essential return contract and points at the next step. The remaining gap is lifecycle guidance (closing the browser, whether the page persists), which the agent must infer from sibling names alone.

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 description coverage is 100%, so all 12 parameters (including defaults, enums, and timeout capture behavior) are already documented in the schema. The description adds no parameter meaning beyond that, so the baseline 3 applies.

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 ('Open a browser and navigate to a URL') and hints at its place in the workflow by returning a page ID 'for subsequent screenshots'. It does not explicitly name the sibling it hands off to (capture_screenshot) or the cleanup counterpart (close_browser), so sibling differentiation is only implied.

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?

Usage is only implied: the phrase 'for subsequent screenshots' suggests this is the setup step before capture_screenshot, but the description never states when to use this versus alternatives, or that a session must be closed afterwards with close_browser. No exclusions or prerequisites are given.

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