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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context by noting the cache duration (~5 minutes), which indicates data may not be strictly real-time despite the label. This goes beyond annotations and helps set expectations.

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?

The description is extremely concise, using two sentences that front-load the primary purpose and immediately list the key data points. Every word adds value, with no fluff or redundancy.

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?

Given the tool's simplicity (no parameters, no output schema), the description fully covers what the tool returns: total listings, average prices by boat type, and regional distribution. Caching behavior is also disclosed. This is complete for a low-complexity read-only snapshot tool.

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?

There are zero parameters, so the description does not need to explain parameter usage. The schema coverage is 100% (empty props), and the description clearly lists the output content, making it self-sufficient. A baseline of 4 applies for no-parameter tools.

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 clearly states the tool provides a real-time snapshot of the European boat market on Obato, including total listings, average prices by boat type, and regional distribution. This specific scope distinguishes it from siblings like get_market_stats, which may cover broader or different metrics.

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 description implies usage for obtaining a quick market overview but does not explicitly state when to use this tool versus alternatives like get_market_stats or search_boats. No exclusions are provided, and there is no guidance on scenario-based selection.

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