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

Annotations already declare readOnly=true, idempotent=true, destructive=false, openWorld=false, so the safety profile is covered. The description adds substantial non-annotation context: no authentication/account requirement, that delivery is free and instant, the non-removable hosted payment element, and the downstream workflow of returning the styled file. Return format and any rate limits remain unstated.

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 first sentence front-loads the purpose well, but the body is a single dense paragraph with nested parentheses (template names, data-yetty grammar references, and the Live-plan aside crammed into one trailing parenthetical). Every clause carries information, yet scannability suffers and the constraint rules are buried mid-paragraph rather than surfaced.

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 one-parameter, annotated, read-only fetch with no output schema, the description supplies everything an agent needs: what is returned, the available variants, the mandatory invariants after restyling, the no-JS rule, and the next action. Nothing material is missing given the richness of the annotations.

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% and the schema already lists the four keys, but the description goes beyond it by explaining the content and purpose of each template (checkout markup, buyer account page, order confirmation, payment frame) and the default. That semantic enrichment of the enum-like values adds real value over the schema baseline.

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 gives a specific verb ('Pull'), a well-defined resource ('a ready-made Yetty template file WITH its usage contract'), and enumerates the four concrete template variants with what each contains. It also distinguishes the base templates from the gallery-<surface>-<layout> layouts, so an agent can tell exactly what it is fetching.

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?

It states the operating conditions clearly (no account needed, free, instant), the redesign freedom ('restyle freely'), the hard exclusions ('NEVER remove or rename data-yetty-* marks', 'write NO cart/checkout/account JavaScript'), and the follow-up step ('send the styled file back'). It does not spell out when to prefer yetty_authoring_guide versus this tool, only cross-referencing it for grammar, so it stops short of explicit alternative routing.

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