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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context beyond annotations: while the plan is DRAFT, the sentinel does nothing, and activation is the user's opt-in. It also clarifies the behavior of refresh_snapshot as running a fresh survey, which is a behavioral trait not captured by annotations.

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 well-structured with a clear lead sentence, a behavioral note about DRAFT plans, then Args and Returns sections. It is appropriately sized—every section earns its place and the most important information is front-loaded. No filler words or repetition of annotations.

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 optional parameter and no output schema, the description is nearly complete. The Returns section gives the output shape {plan: {...}, snapshot?: {...}} and the plan content is described in the first sentence. The internal structure of 'plan' is not detailed, but because the tool is read-only and the plan's content is explained, nothing critical is missing for an agent to call it correctly.

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 carries the full burden for refresh_snapshot. The Args section fully explains what the parameter does (runs a fresh survey of finances), what it includes (upcoming bills, income cadence, available funds), how it affects output (adds a 'snapshot' field), and when it's useful. This exceeds what a schema-only description would provide.

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 states a specific verb ('Get') and resource ('the user's agent monitoring plan'), and elaborates on exactly what the plan contains: bill coverage, low balance, idle surplus, cashflow shortfall, anomalies, and check-in cadence. This clearly distinguishes it from any sibling like update_monitoring_plan or get_setup_status.

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 context is clear: this tool retrieves the monitoring plan and optionally refreshes a snapshot. The refresh_snapshot parameter includes the use case 'useful when helping the user set up or review their plan.' It does not explicitly name alternative tools or state when not to use it, so it falls short of a 5 but is clearly context-rich.

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