Lokalise MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions that the tool 'Returns: Added languages with IDs', which is helpful output information. However, it lacks details on permissions needed, rate limits, error conditions, or whether this is a synchronous/asynchronous operation. The 'Tip' about checking system languages adds some practical context but doesn't fully compensate for the missing behavioral traits.

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?

The description is efficiently structured with three sentences that each serve a distinct purpose: stating the action, specifying parameters, providing usage context, and offering a practical tip. There is no wasted language, and key information is front-loaded, making it easy to scan and understand quickly.

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?

Given the tool's moderate complexity (adding languages to a project), no annotations, and no output schema, the description does an adequate job but has gaps. It covers the purpose, parameters, and a usage tip, but lacks details on authentication requirements, error handling, or the structure of the return value beyond mentioning IDs. For a mutation tool with no structured safety hints, more behavioral context would be beneficial.

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 the schema already documents all parameters thoroughly. The description adds minimal value beyond the schema by mentioning that 'lang_iso' is required and listing optional fields, but doesn't provide additional semantic context (e.g., examples of valid ISO codes beyond what's in the schema, or when to use custom fields). This meets the baseline for high schema coverage.

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 clearly states the specific action ('Starts translating into new languages by adding them to the project'), identifies the resource ('project'), and distinguishes from siblings like 'lokalise_update_language' or 'lokalise_remove_language' by focusing on addition rather than modification or removal. It provides a precise verb+resource combination that is immediately understandable.

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 description explicitly states when to use this tool ('Use when expanding to new markets or adding regional variants'), which gives clear context for its application. However, it does not mention when NOT to use it or name specific alternatives (e.g., 'lokalise_update_language' for modifying existing languages), which prevents a perfect score.

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