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

Beyond the annotations, it discloses that no message is sent, that only the owner can act (auth constraint), that an email is also dispatched, and that the link is the actionable return value. The idempotency statement reinforces idempotentHint=true in context rather than contradicting it, and nothing conflicts with destructiveHint=false.

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-loaded with the action and compact at four short sentences, but the sentence 'Nothing is sent: only the owner can, after reading the country rules, from the link this returns' is grammatically tangled and costs a beat of parsing.

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-parameter request tool with annotations and an output schema, the description covers action, precondition, side effects, authorization, follow-up and idempotency. Nothing an agent needs to invoke it correctly is missing, and the return link is noted even though an 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 single required parameter already documented as 'The campaign's id (cmp_…)', so the description does not need to explain it. The description adds no format or syntactic detail beyond the schema, so the baseline 3 applies.

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+resource with scope: 'Ask the account's owner to launch a draft, or resume a paused campaign.' An agent can distinguish this from create_campaign, pause_campaign and stop_campaign without inspecting schemas, and it makes clear the tool only requests rather than performs the launch.

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 an explicit precondition ('Call it when get_campaign shows nothing left to fix'), names the sibling that gates it, and tells the agent what to do next ('give the user the link'). It also implicitly excludes re-calling by noting 'Asking again changes nothing.'

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