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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds meaningful context beyond that: the data provenance warning ('shows what a competitor published, never what worked') and the fact that offers are returned quoted with change history. It doesn't cover pagination or volume limits, keeping it below 5.

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?

Three tight sentences, front-loaded with what is returned before the provenance caveat and Space scoping. No filler, though the Space sentence is somewhat dense.

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?

No output schema exists, and the description explicitly characterizes the return shape (quoted offer elements, headline offer, change history), so an agent knows what it gets. With annotations covering safety and full schema coverage, nothing essential is missing.

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 both parameters are already documented, including the space_id override semantics. The description echoes the Space behavior but adds no new detail on competitor_id. Baseline 3 applies.

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 the resource precisely - offer elements (prices, discounts, trials, guarantees, deadlines) extracted from a competitor's active ads, with quotes and the headline offer. The caveat that library data shows what was published, not what worked helps distinguish it from performance-oriented siblings like get_performance_stats. However, it never names list_competitor_ads, leaving the closest sibling undifferentiated.

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 Space scoping guidance is clear (uses active Space, switch via set_active_space, or override with space_id). But there is no explicit when-to-use vs list_competitor_ads or get_competitor, and the 'never what worked' note is interpretive caution rather than selection guidance.

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