read_page

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

With no annotations provided, the description carries the behavioral burden. It discloses that the tool returns rendered innerText reflecting what a person sees rather than raw markup, which is valuable behavioral context beyond the tool's name. It does not discuss side effects or failure modes, but the read-only nature is strongly implied.

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 well-organized: a one-line summary, a concise rationale for preferring this tool, then a compact Args block. Every sentence earns its place, and the most decision-relevant guidance ('prefer it over screenshots') is front-loaded.

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?

All three parameters are explained sufficiently for correct invocation, and the output schema likely covers return details. Minor gaps remain—what happens when selector matches multiple elements, and how read_page compares to find_elements—but the core usage context is complete for an agent.

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%, so the description fully compensates. It explains tab as an index within window 1 or a URL/title substring, defines selector as optional CSS that defaults to the whole page, and clarifies max_chars truncation with its 8000 default. This adds meaning far beyond the bare schema.

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 states a specific verb ('read') and resource ('visible text of a tab, or of one element inside it'), and explicitly contrasts itself with screenshots and raw markup ('rendered text (innerText)... rather than raw markup'). This makes the tool's purpose unmistakable and differentiates it from siblings like find_elements and run_js.

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?

It gives clear invocation guidance: prefer this over screenshots, omit selector to read the whole page, and use selector to target a specific element. It does not explicitly say when not to use it or directly name sibling alternatives like find_elements, but the context is sufficient for an agent to route correctly.

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