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

Annotations already declare read-only, idempotent, closed-world, non-destructive behavior, so safety is covered. The description adds real context beyond that: exactly which dimension ranges, depths, and wall heights the tables cover and that the factors used are returned. It doesn't state whether the results are exhaustive/finite or that no computation is performed on custom sizes, but the scope enumeration largely implies this.

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 usage trigger, followed by return contents and the alternative routing. The dimension enumerations are dense but each earns its place by telling the agent exactly which sizes are answerable; minor verbosity in listing ranges twice.

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?

Output schema exists and annotations cover the safety profile, so the description only needs purpose, scope, and routing — all present. An agent knows when to call it, what it will get back, and where to go otherwise.

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 single `kind` enum is fully documented in the schema, including the default. The description indirectly maps its two table families to the enum values but adds no syntax or format detail beyond the schema, so 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 a specific resource (standard pool size gallon tables) with the coverage scope (inground rectangles and above-ground round/oval) and names the sibling tool to use for anything else. An agent can distinguish it from pool_volume without opening either schema.

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?

"Use this when someone asks how many gallons a common pool size holds..." gives concrete triggering examples, and "For any other size or shape use pool_volume" explicitly routes to the alternative with the deciding condition.

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