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

Annotations already cover readOnly/idempotent/non-destructive, but the description adds real behavioral context: it is free and not counted against tasks, it reads only Adako's database, it defines 'task' as one billable tool call, and it explains that a switched-off ad account keeps its plan slot.

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?

Front-loads the read-only/cost guarantee before the return payload and the trigger conditions, and the trailing definitions of 'task' and account retention each earn their place.

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?

No output schema exists, but the description enumerates the returned fields (plan, tasks used vs limit, reset, ad accounts vs limit, plans link), so an agent knows what it will get; safety and cost are also fully covered.

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?

Only one optional parameter (raw_data) and schema description coverage is 100%, so the schema already documents it fully; the description adds nothing about the parameter. Baseline 3 is appropriate here.

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?

Names a specific verb+resource (returns the user's plan, task usage vs limit, reset time, ad-account usage, plans link) and enumerates the exact payload, so it's clearly distinct from siblings like list_connected_accounts or diagnostics.

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 triggers: 'use when a tool returned quota_exceeded or account_limit, or the user asks how many tasks or accounts they have left.' That is a concrete when-to-use rule an agent can act on without inference.

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