read_browser_tab

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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description does add one genuine behavioral constraint — it reads only the *visible* text, not full DOM/hidden content — which is useful scoping, but it says nothing about truncation, error behavior for a missing/ambiguous tab, or whether it waits for load.

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-loaded one-line purpose followed by a tight Args block; nothing is padded. Minor structural noise from the trailing quote/newline in the description string, but the substance is efficient.

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 single-parameter read tool with no output schema, the core is covered: what it returns (visible text) and how to identify the tab. What's missing is failure handling — an ambiguous title like "MATH 115" matching multiple tabs, a closed tab, or non-Chrome frontmost app — which an agent would need to call this reliably.

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 0% and the schema only names the field 'tab' as a plain string, so the description carries the full burden — and it delivers, spelling out three accepted identifier forms (number "3", window.tab "1.3", or title/URL text "MATH 115"). That is meaningfully more than the schema provides.

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 (Read) and resource (visible text of a Chrome tab), and the clarifying phrase 'the way to see what's on a page' pins down what it returns. It does not, however, contrast itself with the obvious siblings that also expose page content, such as screenshot or read_pdf.

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?

There is no statement of when to prefer this over list_browser_tabs, screenshot, or read_pdf, and no prerequisites (e.g., tab must be open, Chrome must be running). The only hint is the implied 'to see what's on a page', which is essentially a restatement of purpose rather than routing guidance.

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