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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false. The description adds genuine behavioral context beyond that: the input key conventions (ITRANS/Baraha, capitals for long vowels/retroflex, M=anusvara, H=visarga) and the sound-based rather than meaning-based interpretation. It does not describe the return format, but annotations carry the safety profile.

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-loads the purpose and examples before the key-convention details. Dense but each sentence contributes; only minor verbosity in listing conventions that could be looked up via get_keymap.

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 two-parameter, no-output-schema tool this is nearly complete: purpose, examples, input conventions, and a pointer to get_keymap. The main gap is that it doesn't hint at error/fallback behavior for unsupported languages or the expected return shape.

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%, so both parameters are already documented. The description still adds value by explaining the key conventions governing how the 'text' parameter is interpreted and giving language examples ('hi', 'ta', 'sat'), going beyond the schema's raw param descriptions.

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 (writes/transliterates) and resource (romanised Latin text → Indian script), and provides concrete examples for Hindi and Tamil. It explicitly distinguishes itself from translation and its purpose is clearly separable from siblings like convert_script.

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?

Clarifies the key semantic distinction ('transliteration, not translation: spell the words as they sound'), which tells the agent when this tool applies. It routes to get_keymap for exact per-language keys, but does not explicitly contrast with convert_script or list_languages.

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