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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds one useful behavioral fact — 'requires read scope' — which is a real authorization prerequisite not expressed in the annotations, but it says nothing about pagination behavior, ordering, or the fact that results are scoped to pending items only.

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 short sentences with zero waste; the scope-defining condition is front-loaded, and the auth requirement follows. Nothing extraneous.

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 simple read-only list tool with full schema coverage and no output schema, the description covers purpose, scope, and the auth requirement. Minor gaps remain — no mention of filtering by campaign_id or result ordering — but nothing an agent needs to invoke 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 description coverage is 100% with self-documenting params (page, page_size with default/max, campaign_id filter), so the baseline is 3. The description adds no meaning beyond the schema — it never mentions the campaign_id filter or pagination, which the schema already handles adequately.

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?

Clear verb ('list') plus a specific resource state ('messages awaiting approval before sending'), which scopes it well against the many other list_* siblings. It doesn't explicitly name an alternative such as get_campaign_chat_messages, but the 'pending approval' qualifier makes the audience unambiguous.

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 phrase 'awaiting approval before sending' implies the context of use — reviewing the outbound approval queue, likely ahead of approve_message. However, there is no explicit when-to-use/when-not guidance and no named alternative, so the routing is left for the agent to infer.

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