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

Annotations already declare a pure read/idempotent operation, so the bar is lower, yet the description still adds real behavior: out-of-range numbers are clamped to the family's limits rather than erroring, omitted params keep defaults, and the call returns the link plus a description of the view. It does not say whether the returned link is short-lived or hostable elsewhere, which is the one remaining gap.

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 purpose, then usage, then behavior, then coordinate semantics — a sensible order with no filler. The first sentence is long and list-heavy, but every clause carries scope 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?

No output schema exists, and 'Returns the link and what it shows' is a reasonable but slightly vague account of the return value. For a six-parameter tool with a nested params object, the description plus the fully documented schema cover what an agent needs to call it correctly.

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 the schema already documents every property including the '(or yaw for 3D)' note on x and y. The description's centre/zoom paragraph mostly restates that, adding only that zoom means camera distance for 3D families — genuinely useful but a small increment over structured data. Baseline 3 is correct here.

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 verb and resource ('Build a link that opens fractals.slopped.site on one exact view') and then enumerates the dimensions being fixed: family, parameters, palette, viewing position. The family list gives concrete scope, and no sibling tool does anything comparable, so an agent can select it unambiguously.

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 when someone wants to see or share a particular fractal' gives a clear triggering condition. There are no exclusions or alternatives named, but the sibling set contains nothing overlapping, so the omission is low-cost.

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