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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=false; the description adds valuable context by promising that replies are matched exactly and never guessed, so the data belongs to the end-user. Costs and latency are also disclosed. No contradiction with annotations.

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?

The description is well-structured with distinct sections: overview, examples, WHEN TO USE, WHEN NOT TO USE, cost, and latency. The core purpose is front-loaded and each section earns its place with actionable information, though the example queries add some length.

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 tool with three well-described parameters and no output schema, it adequately states what data is returned, when to call it, and a rate limiting caution. It doesn't detail return structure or errors, but gives the agent enough to select and use the tool correctly.

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%, so the schema fully documents each parameter. The description contributes a usage example and notes conversation_id is preferred, but it does not add substantial meaning beyond what the schema already says about reference, business_number, and conversation_id.

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 starts with a specific verb and resource: 'Read a two-way conversation thread you started,' and enumerates exactly what it returns: state, every message exchanged, and reply count. This clearly differentiates it from siblings like get_status or get_outcome because it is uniquely about conversation threads.

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?

An explicit WHEN TO USE section states it should be called after send_message returns a conversation_id, in order to poll for the business's reply. The WHEN NOT TO USE section adds a real constraint: don't poll more often than every 10 seconds. It doesn't explicitly recommend an alternative sibling, but the trigger condition is concrete and sufficient.

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