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

Annotations declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false. The description adds critical behavioral context beyond annotations: it specifies the return payload (language list and translation count), notes that translations occur before saving, and warns that large projects can time out. However, it doesn't elaborate on the destructive nature (e.g., what data is overwritten or affected).

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?

Three tightly packed sentences that are front-loaded with purpose and usage, then behavioral details. No wasted words; every sentence adds value.

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 complexity (dual add+translate operation), the description covers what the tool does, when to use it, what it returns, and key caveats (timeout risk). With an output schema present, it doesn't need to detail return values. Annotations cover safety aspects. Nothing critical is missing for an agent to decide and invoke correctly.

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 all parameter descriptions are in the schema. The description adds no parameter-level details beyond what the schema provides. It mentions 'language' and 'strings' generically but doesn't map to specific parameters like locale, model, or context.

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 (add) and resource (language/locale), with the implied translation action. Distinguishes from siblings clearly - no other tool handles adding a locale. The description makes the dual nature (add + translate) explicit.

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?

Explicitly states when to use ('when someone asks to add a new language...') and provides a clear exclusion ('Not for a language the project already has'). This prevents the agent from attempting to add an existing locale.

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