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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the bar is lower, yet the description adds real context: the plan requirement (Business and Agency) and the fact that it does not trigger a send. The most valuable addition is "Only the fields sent change," which clarifies partial-update semantics beyond what the annotations convey. It does not explain why the call is flagged destructive or what happens to the report email when an empty string is passed.

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?

Three short sentences, front-loaded with the operation and its editable surface, followed by the two behavioral caveats. Nothing is repeated from the title or schema and every clause carries information.

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?

With no output schema needed, full schema coverage, and annotations carrying the safety profile, the description supplies exactly the missing pieces: plan restriction, non-sending behavior, and patch semantics. An agent has enough to call this correctly and knows what it will not do.

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 100%, so baseline is 3; however, "Only the fields sent change" adds non-redundant semantics — this is a partial patch, not a full replace — which an agent cannot read from the schema alone. The field enumeration also maps neatly onto reportEmail/reportEnabled/reportFrequency/reportIncludeCharts/reportIncludeIncidents.

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 and resource — changing a monitor's scheduled client report — and enumerates exactly which aspects (on/off, recipient, schedule, charts, incidents) can be changed, which separates it from the update_alerting/update_basics/update_content siblings. It never names a sibling tool outright (e.g. vs_monitor_report_get for reading), so it stops short of full differentiation.

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?

"It does not send a report now" implicitly steers an agent away from expecting an immediate send, but there is no explicit routing to alternatives (vs_monitors_check_now, vs_monitor_report_get) or statement of prerequisites beyond the parenthetical "(Business and Agency)" plan gating. Usage context is implied rather than stated.

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