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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds useful behavioral detail beyond annotations: characters without an upside-down equivalent are kept but still reversed in position. This gives the agent accurate expectations about edge-case handling.

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?

Two focused sentences state the core behavior, the fallback for unsupported characters, and a source link. Every sentence earns its place, and the key behavior is front-loaded.

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, pure transformation tool with an output schema and safety-related annotations, the description covers everything an agent needs to invoke it correctly. The fallback behavior and reversal detail make the tool's behavior fully predictable.

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?

There is a single required parameter with 100% schema description coverage ('The text to flip upside down'), so the schema already documents it fully. The description reinforces the meaning but adds no format, length, or encoding constraints 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 uses a specific verb ('Flip'), names the resource ('text'), and explains the mechanism (Unicode look-alike characters plus reversed order) so the result is clearly a 180-degree rotation. This distinguishes it from siblings like hopi_reverse_text, which only reverses order without the character substitution.

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 described use case is clear: any text that should appear rotated 180 degrees. It does not explicitly name alternatives or state when not to use it, but the mechanism and output behavior are specific enough that an agent will not confuse it with simple reversal or other text-transform tools.

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