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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds genuinely useful behavioral context beyond that: the 2-4 range, the same-market scoping requirement, and what the comparison surfaces (prices, scores, capabilities). It still doesn't say what happens when ids come from different markets, but this is solid against an already-rich annotation set.

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 that states the action, the arity constraint, and the comparison dimensions with no filler. Nothing could be removed without losing information.

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 one-parameter read-only comparison tool with full annotations, the description covers the essentials and even sketches the return content. With no output schema, a slightly more explicit statement of the comparison result (e.g. a side-by-side table vs. per-field breakdown) would make it fully self-sufficient.

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% and the schema already documents the ids array, its 2-4 bounds, and the same-market constraint. The description restates 'same market' and '2 to 4' without adding format, ordering, or error-handling semantics beyond the schema. Baseline 3 applies when the schema carries the parameter detail.

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 concrete verb and resource: putting 2-4 offerings side by side for comparison, and enumerates the comparison dimensions (prices, scores, capabilities). It clearly differs in intent from get_offering or search_offerings, but it never names a sibling explicitly, so the agent must infer the boundary.

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?

Usage is implied by the phrasing: use this when you want a multi-offering comparison rather than a single lookup. There is no explicit 'use this instead of...' statement, no guidance on what to do when more than 4 ids are needed, and no stated prerequisites.

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