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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds real context beyond that: archived campaigns are excluded, settings JSON is deliberately omitted and where to get it instead, and the returned field set. It does not address ordering, pagination, or scoping/permission limits, which keeps it from a 5.

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?

Scope and exclusion are front-loaded, and each subsequent sentence (return shape, omission rationale plus alternative, status enum) carries distinct information. Slightly dense with nested parentheticals, but nothing is filler.

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, the description must describe returns, and it does: count, a brief one-liner, and the item fields {id, name, status, agent_id, list_id}, plus the allowed status values. For a zero-parameter read tool with full annotation coverage, nothing an agent needs to call it correctly is missing.

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?

The tool takes zero parameters, so the baseline for this dimension is 4. The description appropriately uses no space explaining inputs and instead spends it on scope and outputs.

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?

A specific verb (List) plus resource (campaigns) plus scope (the app the request is scoped to) with an explicit boundary (excludes archived). It names the sibling get_campaign and states exactly what is not covered here, so the agent can distinguish the two without inspecting schemas.

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 clearly routes the agent to get_campaign for workflow, sender, and action detail, and the '(excludes archived)' note sets a usage boundary. It does not state a full when-to-use/when-not-to-use rule set or mention other list-style siblings, so it stops just short of a 5.

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