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

Annotations already establish readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds real value beyond that: it warns that returned content is untrusted data rather than instructions, which is critical prompt-injection guidance for a tool pulling arbitrary web pages, and it flags the output as bounded/hashed.

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 tight sentences with the core action first and the trust warning second; every clause earns its place and nothing is padded.

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?

An output schema exists, so return values need no explanation, and the untrusted-content warning covers the main risk of an openWorld read tool. However, with six parameters at 0% schema coverage and no usage routing against five sibling tools, the definition is not fully complete for correct invocation.

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% across six parameters, so the description carries the full burden and falls short. It gestures at the content hash (known_content_sha256), the change check, and bounded size (max_chars), but leaves include, max_age_ms and response_mode — including the only enum — completely unexplained in both schema and description.

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 and resource ('Fetch a bounded public webpage snapshot') plus two distinguishing capabilities: a content hash and a caller-controlled change check. It doesn't name or contrast against siblings like web_qa or website_audit, so an agent must infer the boundary itself.

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: 'bounded public webpage' signals the eligible scope, and the change-check wording hints at incremental re-fetching. There is no explicit when-to-use statement, no when-not-to-use, and no mention of the sibling tools it competes with.

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