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

Annotations already declare a safe, idempotent, read-only operation, so the safety profile is covered. The description adds value beyond that by disclosing the return content, including 'what stops it going live' (blocking conditions) and stats, which matters because there is no output schema. It stops short of naming the exact blocking fields.

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?

A single front-loaded sentence that leads with the resource and then enumerates the contents. It is dense with parenthetical lists but every element earns its place; no 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?

For a read-only single-resource fetch with no output schema, the description carries the burden of describing the return payload and does so by naming the definition fields plus stats and blockers. Nothing critical to invoking 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?

Schema coverage is 100%, and the single messageId parameter is documented in the schema with a cross-reference to list_proactive_messages. The description adds no format or syntax detail beyond that, so the baseline of 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 (get) and resource (a proactive message) and enumerates the returned facets (content, audience, pages, trigger, frequency, schedule, goal). It is clearly a single-resource fetch, though it does not explicitly distinguish itself from the sibling get_proactive_message_report, whose domain overlaps with the 'stats' it promises.

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?

There is no explicit when-to-use or when-not-to-use guidance. The only routing signal is implicit: the schema's messageId description points to list_proactive_messages, implying the fetch flow starts from a listing. Adequate but reliant on inference.

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