service_compare

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

Annotations already establish that this is a read-only, idempotent, non-destructive, closed-world operation. The description adds a meaningful behavioral caveat beyond the annotations: it produces no automatic winner and no fabricated scores, which helps set expectations for the comparison output.

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, front-loaded with the core purpose and followed by the most important output caveat. There is no wasted language and the useful limitation is easy to see.

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 description is minimally adequate given that an output schema exists and annotations cover safety semantics. However, the zero-coverage parameter schema leaves the family values and constraints format under-explained, and the description does not compensate for that gap.

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 must carry the burden of explaining parameter meaning. It only restates that there is a service family and user constraints; it does not explain the enum choices, what each family contains, or what format constraint strings should take.

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: compare curated AWS service families against user constraints. It does not explicitly name a sibling tool or explain why it differs from service_equivalents, but the scope is clear enough to distinguish it from most siblings.

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 implies the tool is used when comparing service families against constraints, but it gives no explicit guidance on when to choose it over alternatives such as service_equivalents or aws_knowledge_search. There are no exclusions or prerequisite conditions.

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