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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds 'inline' display behavior and accepted image categories, while the schema adds host restriction. These are useful behavioral details beyond the annotations.

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?

A single front-loaded sentence with no wasted words. It efficiently states the action and gives examples of accepted image types.

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 simple one-parameter viewer with safety annotations, the description plus schema are nearly complete. 'Show inline' conveys the return behavior in the absence of an output schema, and the schema covers host refusal, though more detail on output format could help.

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?

With 100% schema description coverage, the single URL parameter is already well documented in the schema, including the host restriction. The description's enumeration of image categories overlaps with the schema and adds only slight contextual value.

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 ('Show') and resource ('Framesail image inline'), and enumerates image categories (segment, reference, style template, preset preview). It does not explicitly differentiate itself from sibling read tools, but the purpose is clear.

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 use for viewing images sourced from read tools, and the schema states that other hosts are refused. However, it gives no explicit when-to-use/when-not guidance and does not name alternatives among the many sibling tools.

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