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

Annotations already provide destructiveHint=true and idempotentHint=true, covering the mutation safety profile. The description adds useful context by explaining that project names are intentionally unchanged because phrases reference the name. However, it does not itself disclose that replacing the locale list can remove omitted locales; the schema handles that detail.

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 concise sentences with no filler. The first sentence packs the full purpose, and the second adds a valuable constraint with rationale. It is front-loaded and every sentence earns its place.

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, 100% parametr coverage, and annotations for destructive/idempotent behavior, the description is largely sufficient. The only implicit aspect is how optional parametrs interact when omitted, but the schema's 'complete replacement list' and defaultLocale requirements reduce the risk. Slightly more explicit note about partial updates could make it fully complete.

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%, and each parametr already has detailed descriptions, e.g., 'Complete replacement list of locale codes' and 'New default locale code. It must be one of the project locales.' The description summarizes the three updatable areas but does not add new meaning beyond the schema, so baseline 3 is appropriate.

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 verb 'Update', the resource 'MultiLocale project', and the exact editable fields: default locale, complete locale list, and translation context. It also explicitly names a non-goal (project names are intentionally not changed) and distinguishes itself from sibling tools like update_phrase and add_locale.

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?

It gives clear context about when to use this tool: when updating locale settings or translation context. The explicit statement that project names are not changed is a clear exclusion, and 'complete locale list' implies replacement semantics rather than single-locale addition. It does not explicitly name sibling alternatives like add_locale, so it stops short of a perfect score.

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