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

With no annotations, the description carries the full burden. It says nothing about whether this is read-only, what the comparison output contains, ordering behavior, or what happens if fewer than 2 IDs are supplied.

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?

A single front-loaded sentence with no waste, though the parenthetical spec list sits awkwardly at the end.

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 comparison tool with no annotations and no output schema, the description is minimally adequate but omits mutuality of ids vs id_a/id_b and any behavioral expectations.

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 coverage is 100%, so the schema already documents ids, id_a, and id_b. The description adds the '2–4 machines' range, but not the relationship between ids and the id_a/id_b alternative.

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 (compare) and resource (machines) with scope detail (2–4 machines, comparing specs and price). It distinguishes itself from siblings like search_machines or get_machine_detail, though it doesn't explicitly name alternatives.

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?

Implied usage when comparing multiple machines, but no explicit when-to-use guidance or exclusions versus get_machine_detail for single-machine lookups. The 2–4 count constraint hints at scope but isn't framed as guidance.

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