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

There are no annotations, so the description carries the behavioral disclosure burden. It does disclose that missing inputs fall back to documented defaults, which is useful. However, it does not clarify whether the tool is read-only/calculation-only, what the returned structure looks like, or whether there are any side effects.

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 short and front-loaded, but it contains a redundant phrase ('calculator calculator') and the semicolon-separated list reads awkwardly. Every item is relevant, but the wording is not polished enough for a higher score.

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 calculation tool with seven optional parameters, no output schema, and no annotations, the description gives a reasonable high-level picture and notes default fallback behavior. It is missing explicit output-format or return-shape information, so it is adequate but not 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 100%, so the schema already documents all seven parameters well. The description adds only the general fallback behavior and high-level calculation categories, which is useful but does not materially improve parameter-level understanding beyond the schema.

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 specific action ('Run the Boat value calculator') and lists the calculation aspects it covers: engine-hour adjustment, condition adjustment, indicative value, and percentage of guide value. It does not explicitly differentiate from sibling tools like calculator_describe, so it gets a 4 rather than a 5.

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 when to use the tool ('Run the calculator') but gives no explicit guidance about when to choose it over alternatives such as calculator_describe or submit_enquiry. There are no conditions, exclusions, or hints about which sibling serves a different purpose.

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