fast_browser_diff

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

With no annotations, the description carries full burden for behavioral disclosure. It implies a read operation by stating 'Return', but does not mention whether the operation is safe, idempotent, or has side effects. Critical behaviors such as what happens if no diff exists, authentication requirements, or rate limits are omitted.

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 concise in word count (one sentence) but is under-specified for an agent to use effectively. It sacrifices necessary details for brevity, making it too sparse. While it avoids fluff, it omits important information that should be included.

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 tool has one required parameter, no output schema, and no annotations, the description should compensate but fails to do so. It does not explain what a diff is, the output format, error conditions, or behavior when no diff exists. This is insufficient for an agent to correctly invoke and interpret results.

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%, and the description adds no meaning to the sessionId parameter beyond what the schema provides (string, minLength 1). It fails to explain how the sessionId is used, format expectations, or constraints. For a single-parameter tool, the description should at least clarify the parameter's role.

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 verb 'Return', the resource 'latest saved diff', and the context 'for a session'. It effectively distinguishes from sibling tools like fast_browser_snapshot and fast_browser_state, as it specifically retrieves a diff. However, it could be more explicit about what a 'diff' entails, such as comparing two snapshots.

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 no guidance on when to use this tool versus alternatives. There is no mention of prerequisites, when it is appropriate, or when other tools like fast_browser_snapshot or fast_browser_report might be preferred.

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