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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's safety disclosure is redundant. However, it adds significant behavioral context beyond annotations: the silent risk of name lookup resolving to the wrong offer due to prefix matching, the precedence of offer_id, and the exact return content for each mode. This is valuable and not contained in the 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 compact and front-loaded with the core purpose, followed by concise usage examples and a clear behavioral breakdown. Every sentence contributes value—no filler or repetition. It is well-structured for quick agent parsing.

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 two optional parameters, no output schema, and annotations covering safety, the description sufficiently explains both invocation modes and the return contents ('detailed offer info' vs. 'list of all available offers'). It does not detail pagination or error cases, but for a read-only lookup tool this is acceptable and unlikely to confuse an agent.

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 input schema provides 100% coverage for both parameters, including descriptions of behavior and precedence for offer_id. The tool description repeats these points but adds no new parameter-specific meaning beyond what the schema already documents. Thus, it meets the baseline of 3 for high schema coverage, but does not elevate further.

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 states a specific verb and resource: 'Get offer information by name or list all offers.' It clearly distinguishes two modes based on whether a name is provided, and the usage examples make the purpose unambiguous. It is differentiated from sibling tools like create_update_offer (write operation) and find_offer_url (different resource) by the focus on retrieving offer details.

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 description provides explicit 'USE FOR' examples and conditional behavior: if name provided vs. if not. It also advises preferring offer_id over name and explains why, which is actionable guidance. It does not explicitly mention alternatives like find_offer_url, but the purpose is distinct enough that the agent can infer when to use this tool.

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