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

Annotations already cover read-only, idempotent, non-destructive and closed-world behavior, so the bar is lower. The description still adds real value beyond them: it enumerates what the comparison returns (dated specifications, setup requirements, strengths, limitations, sources) and states an explicit behavioral constraint — no overall score or invented compatibility — which is a meaningful guardrail an agent could not infer from structured fields.

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 tight sentences, front-loaded with the core action and scope, followed by the output dimensions and the negative constraint. Every clause carries information; nothing is redundant padding.

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 no output schema, the description usefully names the sections a comparison contains, so an agent knows what to expect back. Gaps remain around the language parameter and ID validation behavior, but for a simple read-only two-parameter tool the core picture is complete.

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 parameter meaning. It partially does for machineIds (two to four known IDs), though the schema already encodes minItems/maxItems, and it never mentions the lowercase-hyphen ID format. The language parameter is not mentioned at all, leaving a required-to-call choice undocumented.

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 and resource (compare machines) and pins the scope: two to four *known* machine IDs, compared across named dimensions. The word 'known' implicitly separates it from the discovery sibling find_machines, but that sibling is never named, so differentiation is inferred rather than stated.

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?

'Known machine IDs' implies the caller must already have IDs (i.e. obtained via find_machines), and the 2-4 range is clear. However, no explicit when-to-use/when-not guidance or named alternative appears, and nothing says what happens if an unknown ID is supplied.

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