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

Beyond the readOnly/idempotent/openWorld annotations, it discloses the lossiness of romanization, the two distinct result modes (source=dictionary vs source=reconstruction, approximate=true), that reconstruction is a guess rather than attested, and that caching causes non-deterministic results over time. This is exactly the behavioral context annotations cannot carry.

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-loaded with the core purpose and the inverse relationship to latgalian_romanize, then the lookup-vs-reconstruction behavior. Efficient, though the lossiness details slightly duplicate the parameter schema description.

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?

An output schema exists and the annotations cover the safety profile, yet the description still conveys the essential return semantics (dictionary hit vs approximate reconstruction). Nothing an agent needs to call this correctly is missing.

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?

With only one parameter and 100% schema description coverage, the schema already documents the input, its ASCII constraint, the multiple-match possibility, and the recovery limitations. The description restates this material rather than adding meaning beyond the schema, so the 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?

States a specific verb and resource ('Find the real Latgalian word(s) whose romanization matches'), and explicitly positions itself as the inverse of the sibling `latgalian_romanize`. An agent can distinguish it from latgalian_search and latgalian_romanize without opening a schema.

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?

Explains the operating context clearly: it is a lookup against the dictionary cache, with reconstruction as fallback, and notes coverage grows so results may change. It does not explicitly say when to prefer a sibling such as latgalian_search over this tool, so it falls short of full when/when-not guidance.

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