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

With no annotations, the description carries the full burden, and it does so well. It discloses that raw events are omitted unless include_events is true, that the stream is capped at 200 events, and that the verdict is advisory because browser signals can be spoofed by an attacker.

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 compact and front-loaded: the main action appears first, followed by the evidence contents, the conditional event-stream behavior, and a security caveat. Every sentence contributes useful information without repetition.

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?

For a tool with no output schema and no annotations, the description covers the return contents, the optional parameter's effect, and an important caveat about verdict reliability. It does not mention error behavior or how to obtain a valid session_id, but the core calling context is clear.

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%, so the description must add meaning to the parameters. It enriches include_events with concrete behavior and the 200-event cap, and the purpose statement makes session_id's role obvious as the identifier of the visit being fetched, though it doesn't explicitly state where to obtain it.

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: 'Get one website visit and the evidence behind its verdict.' It then enumerates the exact return contents (feature vector, plain-language observations, model reads), which clearly differentiates it from listing, analytics, and site-management siblings.

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 clearly establishes it is for retrieving a single website visit's evidence rather than listing or aggregating sessions. It lacks an explicit statement of when not to use it or which sibling to prefer, but the context is sufficient for an agent to select it appropriately.

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