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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered; the description instead contributes real behavioural detail: letter-by-letter mapping, language preservation, nearest-letter fallback for missing sounds, and pass-through of non-Brahmic text. That fallback/pass-through behaviour is exactly the kind of edge-case disclosure an agent needs and cannot get from 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?

Four short sentences, front-loaded with the core transformation and immediately followed by a concrete Devanagari→Kannada example. Every sentence carries information, though the script enumeration could be tightened.

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?

There is no output schema, so the description's statement that unmapped text is kept as-is usefully implies the return shape (transformed text with pass-through). Error behaviour for unsupported targets is unstated, but otherwise the definition is complete for this low-complexity, two-parameter tool.

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 both parameters are already documented, and the description adds only a worked example of the mapping rather than new parameter detail. Baseline 3 applies when the schema carries the parameter burden.

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 gives a precise verb+resource ('rewrites text from one Indian script into another letter by letter') and enumerates the exact script families handled, which lets an agent separate this from generic Romanisation tools. It stops short of naming the sibling `transliterate` or stating how it differs from it, so sibling differentiation is only implicit.

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?

Usage is implied by the enumerated script set and the note that 'text in other scripts is kept as it is', which tells the agent when this tool will and won't transform input. However, no alternative is named and no explicit when-to-use-this-vs-`transliterate` guidance is given.

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