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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered structurally. The description adds useful content context (what the list contains and why the codes matter) but says nothing about ordering, return shape, or whether the extras are distinguished in the output.

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 sentence, front-loaded with the verb and resource, with the qualifying parenthetical folded in. Every clause carries information; nothing is padding.

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 zero-parameter, read-only listing tool with rich annotations and no output schema, the description covers what is returned and why it matters. Slightly short of complete only because it does not describe the response structure or whether the extra scripts are flagged.

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?

The tool takes zero parameters, so there is nothing to disambiguate; baseline for no-param tools is 4. The description still earns its place by explaining the semantic content of the returned codes rather than leaving them unexplained.

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 and resource (lists languages) and narrows the scope precisely: the 22 scheduled languages of India plus extra official scripts for Kashmiri, Manipuri and Sindhi. No sibling (convert_script, get_keymap, native_digits, transliterate) is a listing tool, and the description makes this one obviously the discovery entry point.

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 clause 'with the codes the other tools accept' implies a clear use case: call this first to obtain valid language codes for the other tools. It gives good context but stops short of explicit when-not guidance or naming which sibling to call next.

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