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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds critical guidance beyond them: goals are saved only in the goals editor by their owner, and the agent must never claim to have set or changed one. It also explains non-obvious semantics like withheld platforms, computed MER, and how `checks` should be interpreted and communicated.

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?

It is dense and front-loads the resource description before diving into field semantics. Most sentences earn their place given the absence of an output schema, though the volume of backticked field names makes it heavier than ideal.

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 and four undocumented parameters, the description still explains the return structure (goals, origins, budgetOrigin/targetOrigin, checks, suggestion bases, withheld platforms) and the vocabulary needed to interpret it. An agent has everything required to both call the tool and narrate its results 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 coverage is 0%, so the description must carry the full burden — and it does. It explains that `month` is YYYY-MM with the current month by default, and that the three numeric parameters are hypothetical values to be judged against history, which is meaning the schema alone cannot convey.

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 names a specific resource — the month's goals register — and enumerates the exact contents: net revenue, media spend, the computed MER target, nCAC target and per-platform budgets. No sibling tool covers goals, and the field-level detail makes the scope unambiguous.

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 gives concrete triggers: use it to judge values the person is considering (by passing netRevenue/totalSpend/ncacTarget) and when asked who set a goal or whether it is Nuira's. No alternative tools are named, but none in the sibling list overlap, so the guidance is sufficient without explicit exclusions.

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