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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so the bar is lower; the description still adds real behavior by disclosing that results are pre-filtered to live campaigns with remaining budget and that the pay model is per 1,000 views. It does not mention pagination, result caps, or sort ordering direction.

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?

Two tight sentences, with the scoping constraint (live, budget remaining) front-loaded before the sorting options. No redundant restatement of the title or the schema.

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?

For a one-optional-param list tool with no output schema, the description covers scope, market model, and ordering adequately. It stops short of indicating what campaign fields come back or how results are limited, which is a minor gap given no output schema exists.

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% with a documented default, so baseline is 3, but the description maps the terse enum values to meaning — 'room per clipper' for room and 'newest' for new — which the schema's bare enum labels do not. This is genuine added value over the structured field.

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 ('Lists live paid clipping campaigns') and narrows the scope to those still having budget left, with a concrete example (Content Rewards). It does not explicitly name a sibling such as get_campaign, so the distinction is inferred rather than stated.

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 description implies when this tool applies (browsing open, budget-backed campaigns) and enumerates the sort modes, which suggests a discovery workflow. It gives no explicit when-not guidance and no pointer to get_campaign for fetching a single campaign, leaving the agent to infer the alternative.

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