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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, while the description adds substantive output context: capital and small forms, numbered pen strokes, direction arrows, stroke playback, trace scoring, printable sheet, and style support. It does not contradict 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?

Two sentences, front-loaded with the core action, and no filler. The feature list is dense but useful, and every phrase contributes to what the agent should expect.

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 single-letter display tool, the description plus 100% schema coverage, rich annotations, and an output schema provide enough to call it correctly. It could be stronger by stating when to choose it over show_alphabet or practice_handwriting.

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 style/alphabet enum meanings, defaults, and print/cursive relationship are already documented in the input schema. The description only lightly confirms "five styles or print" without adding format or interaction details 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?

The description uses a specific verb, "Shows," and resource, "one letter," and enumerates capital/small forms, stroke annotations, playback, tracing, and printable sheet. It is clear, but it does not explicitly name a sibling such as show_alphabet or practice_handwriting to distinguish overlapping cases.

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 implies the use case of viewing a single letter with instructional strokes, but gives no explicit when-to-use or when-not-to-use guidance. The agent must infer its boundary from "one letter" and the listed features without any named alternatives.

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