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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds real behavioral value by disclosing the comparison baseline (same destination, departure month, boat type, drawn from the agent's scans of hundreds of boats) and the shape of the verdict. It says nothing about freshness/staleness of the market data or what happens with an id that has no comparable weeks.

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?

Front-loaded with the comparison and its dimensions, then the outputs, then the usage sentence — a logical order with no filler. The single dense sentence packing baseline dimensions and five output artifacts is heavy but each clause carries 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?

With an output schema present and annotations covering the read-only profile, the description need not restate return formats, and it is complete enough to decide when to call. The remaining gap is the id-versus-url choice, which neither description nor caller guidance resolves.

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 100%, including a worked URL example for id, so the schema carries the parameter burden and baseline is 3. The description adds nothing about the unusual fact that both id and url are optional and how to choose between them, which is the one genuinely ambiguous point for a caller.

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 concrete verb (compares) and a precisely scoped resource: one boat-week's price versus the market for the same destination, month and boat type, enumerating the verdicts and supporting stats it returns. The scope implicitly separates it from compare_boats and search_deals, but no sibling is named outright, 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?

Gives explicit trigger conditions: 'Use it before recommending a boat or when the person asks whether a price is good.' That is a clear when-to-use, though it offers no when-not-to-use or named alternative for situations like comparing two candidate boats, which is what compare_boats appears to cover.

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