Verify what changed

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

Beyond the readOnlyHint annotation, the description discloses detailed behavioral aspects: it returns a diff ID, handles omitted changes by kind, includes geometry-only flags, and clarifies how folded wrappers are treated. It fully explains what happens in edge cases (no baseline, oversized diffs), exceeding annotation information.

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 overly verbose and repetitive. It repeats concepts like 'folded wrappers' and 'geometryOnly' in different phrasings, and the long paragraph lacks clear structure or bullet points. The core information could be conveyed in half the length, making it less efficient for an agent to parse.

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?

Despite verbosity, the description is exceptionally comprehensive. It covers return fields (changes, changesTotal, etc.), edge cases (no baseline, oversized diffs), special flags (geometryOnly), and persistence across navigation. An agent receives all necessary context to understand expected outputs and behaviors without needing additional information.

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 100% for the single optional parameter sessionId, and the description adds no extra semantic detail beyond the schema. The parameter is clearly optional with a default behavior (shared default session), so the schema is sufficient; a score above baseline is given because the description reinforces the optionality and context.

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 that the tool verifies what changed since the last observation, with a specific verb ('verify') and resource ('what changed'). It distinguishes itself from siblings like browser_diff and browser_assert by focusing on verification and returning a diff ID for assertion, making its unique purpose evident.

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?

Explicit guidance is provided: 'Call it after EVERY action instead of comparing screenshots' and 'then pass its diffId to browser_assert to check THIS exact transition.' This gives concrete when-to-use instructions and even directs the next step, leaving no ambiguity about usage.

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