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

Beyond the readOnlyHint annotation, the description adds useful behavioral context: results are fed by token visibility, and results are restricted to the active Space unless overridden. It also hints at return fields, though pagination specifics are left to the schema.

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 information-dense sentences pack in the action, scope, return fields, and optional override. Nothing is redundant; every clause earns its 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?

The description completes the picture for a list tool: it tells what is returned, the scope constraints, and how to adjust scope. Given the schema already documents pagination parameters and there is no output schema, this is sufficiently complete.

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%, so the parameters are already fully described. The description reinforces the space_id parameter's behavior (override for one call) but adds no new detail about limit or cursor, meriting the baseline score of 3.

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 clearly states the action ('List campaigns'), the scope ('visible to this token'), and the returned data shape (array with id, name, type, budget, etc.). It effectively distinguishes from sibling tools like get_campaign and list_campaign_assets by focusing on the campaign objects themselves and Space scoping.

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?

Provides clear context on Space scoping: how the active Space is used, that set_active_space can change it, and that space_id can override one call. However, it does not explicitly reference alternatives (e.g., use get_campaign for a single campaign) or when-not-to-use the tool.

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