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

Annotations only cover the generic safety profile (readOnlyHint=false, openWorldHint=true, idempotentHint=false). The description goes well beyond them: credit costs (40 for speed, 300 for quality), the fact that the balance is checked before anything starts, expected duration of several minutes, and the side effect that 'signup' actually creates a new account. These are exactly the operational traits an agent needs before committing to a paid, non-idempotent run.

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?

Purpose is front-loaded in the first clause, and every subsequent sentence carries operational information (costs, template semantics, URL constraint, polling cadence) rather than filler. It is dense and uses long semicolon-joined sentences, which costs some readability, but nothing is wasted.

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 not be detailed, yet the description still previews the TRACES score, stuck points and replay link. Combined with the credit, prerequisite, and polling guidance, an agent has everything needed to invoke this correctly on the first attempt.

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%, so the baseline would be 3, but the description enriches the parameters beyond the schema: it explains the tier trade-off in cost terms, clarifies that email/password matter only for the signup template and continues into the signed-in home, and notes the purchase template needs no account. It slightly duplicates the schema text, which keeps it out of 5 territory.

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?

States a specific verb+resource ('Start a Menso test on a live website') and then explains the mechanism precisely: an AI persona in a real cloud browser attempting a task, scored 0-100 with a step replay. It also names the sibling tools in the workflow (poll get_status, then call get_findings), so an agent can place it relative to the rest of the toolset without opening other schemas.

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?

Gives explicit selection criteria between the two templates ('purchase' needs no account; 'signup' requires email and password), states the URL must be publicly reachable and explicitly warns against localhost, and prescribes the follow-up pattern (poll get_status every 30-60 seconds, then get_findings). This is when-to-use, prerequisites, and sequencing all in one.

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