Скриншот и структура страницы / Page screenshot and structure

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

Beyond annotations (readOnlyHint, idempotentHint), the description discloses cost (3 credits), output format (inline image + file link + markdown), and context consumption ('The image consumes a lot of context, which makes this tool overkill for reading'). No contradictions with annotations.

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 structured with clear markers ('When:', 'Do not use when:', 'Returns:', 'Cost:') and each sentence carries distinct information. Bilingual repetition is acceptable for internationalization but does not add bloat.

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?

Covers purpose, alternatives, cost, return types, context consumption, and use cases. No output schema is present, but the description adequately explains what the tool returns. Complete for a tool of this complexity.

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 the schema already documents url and maxChars with meanings. The description does not add parameter-specific details beyond what the schema provides, hence baseline 3.

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 opens with a specific verb and resource: 'Opens the page in a full browser and returns a screenshot as an inline image, a link to the full-size file, and the page text in markdown.' This clearly distinguishes it from read_url and extract by emphasizing the visual output (screenshot) and full-page text.

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?

Provides explicit 'when to use' and 'when not to use' guidance, naming alternatives: 'Do not use when: you only need text — read_url (1 credit vs 3, and faster); you need specific values — extract.' This is ideal usage guidance.

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