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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering safety and side-effect expectations. The description adds the 'canonical catalog' qualifier, which hints at a standardized data source, but does not disclose other behavioral traits such as error behavior, plan availability, or whether any filtering is applied. This is a modest addition over 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 a single, front-loaded sentence with no filler. Every word contributes to the core meaning, and it avoids repeating the tool name or title excessively.

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?

The tool is simple, the output schema exists, and annotations cover the safety profile, so the description does not need to explain return values. However, the description omits the meaning of 'canonical catalog' and does not clarify when to use this tool among many similar siblings. These gaps keep it from being fully self-sufficient, though the simple nature of the tool makes it adequate overall.

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 0%, so the description bears the burden of explaining planIds. It only paraphrases the schema's minItems=2 as 'two or more plans' and gives no detail about what planIds represent, how they should look, or where they can be obtained. The parameter semantics are therefore weakly conveyed.

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 ('compare'), a clear resource ('plans'), and a scope qualifier ('using the canonical catalog'). This distinguishes the tool from siblings such as dp_commercial_compare_integration_options (which compares a different resource) and from get_offer/list_offers (which perform different operations).

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 no guidance on when to use this tool versus alternatives like dp_commercial_list_offers, dp_commercial_get_offer, or dp_commercial_compare_integration_options. There are no explicit conditions, exclusions, or references to related tools, leaving the agent to infer usage from the name alone.

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