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

No annotations are provided, so the description carries the full burden. It discloses the auth header, the prerequisite of manual connection, and implies a read-only nature by saying 'Show'. It does not explicitly state that no data is modified, but the verb 'Show' strongly implies it, and there is no contradiction. The description adds context beyond what annotations would provide.

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 sentences with zero waste. The purpose is front-loaded, followed by precise usage guidance and prerequisites. Every sentence earns its place, and the structure is clean and scannable.

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 single-parameter read tool with no output schema, the description fully explains what it returns (ad account and conversions), when to call it, the prerequisite, and the auth requirement. 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?

Schema description coverage is 100% because the parameter has a description ('From list_clients.'). The tool description does not add further parameter meaning beyond that, but the schema already provides the source of the value. Baseline 3 is appropriate since the schema carries the parameter explanation.

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 ('Show') and resource ('client's connected Facebook ad account and the conversions available'), clearly distinguishing it from sibling tools like list_clients and build_paused_campaign. The description explicitly names the sibling it pairs with and the scenario, leaving no ambiguity about what this tool does.

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?

Explicitly instructs when to call this tool ('Call this before build_paused_campaign on a leads or sales campaign') and explains why (those need a conversion to aim at). It also notes a prerequisite (manual Facebook connection) and the auth requirement (X-Mako-Key header), providing clear guidance on when and how to use it.

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