browser_snapshot

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

With no annotations provided, the description fully bears the burden. It discloses that refs are attached via data-mcp-ref and are valid until next navigation, explains the tradeoffs of different modes, and describes the caching behavior of diff_from_last. This provides comprehensive behavioral understanding.

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-structured with clear sections for modes and diff_from_last. It is somewhat lengthy but each sentence adds value. Minor redundancy could be trimmed, but overall it 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?

Given the presence of an output schema (though not shown), the description does not need to detail return values. It covers purpose, modes, and caching behavior adequately. However, it lacks mention of prerequisites, side effects, or what happens if called before navigation, which would improve completeness.

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 coverage is 0%, so the description must add meaning. It thoroughly explains both parameters: the mode parameter's three options with their performance and fidelity differences, and the diff_from_last boolean's caching mechanism. This goes well beyond the schema's minimal definitions.

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 clearly states the tool injects SNAPSHOT_JS and returns a ref-indexed list of interactive elements. It distinguishes itself from siblings like accessibility_snapshot and navigate_and_snapshot by focusing on interactive elements and performance tradeoffs.

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?

The description provides explicit guidance on when to use each mode (full, fast, viewport) based on performance vs completeness tradeoffs, and explains the diff_from_last option. It implies usage for taking snapshots after navigation but does not explicitly mention when not to use it or list alternatives.

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