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

Annotations declare destructiveness, idempotency, and write access, and the description adds real context on top: updates merge rather than replace, and an empty-string value clears a path back to the source-language fallback — which directly explains the destructive hint. It also exposes the plan/entitlement requirement, though it does not discuss error behavior for invalid paths.

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?

Two compact sentences with the core merge semantics and the clearing rule front-loaded, followed by the plan requirement. No filler, and every clause carries information.

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?

With an output schema present, return values need no explanation, and the description covers merge behavior, the clear-to-fallback case, and the plan gate. Only edge cases (unknown paths, validation failures, size limits) are left unaddressed.

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 all three parameters are already documented, including the merge and empty-string-clearing rules the description repeats. The description adds no path syntax, key-format, or batching detail beyond the schema, so the baseline of 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 (merges) and resource (a locale's translation content), and the merge framing distinguishes it from create_translation/delete_translation and from a whole-object replace. It does not name a sibling explicitly, so it falls short of a 5.

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 gives a prerequisite ('Requires the Build plan or higher') but never says when to choose this over create_translation, delete_translation, or get_translation. Usage is implied by the verb rather than stated, and the schema is left to point at list_translations for obtaining the id.

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