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

With destructiveHint and idempotentHint already present, the description adds important update semantics: omitted fields keep their values, while a new locales list replaces the entire set. This clarifies exactly which kind of destructive behavior to expect and complements the annotations rather than repeating them.

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 three tightly written sentences: use case first, update semantics second, exclusion last. Every sentence carries operational information, with no filler or repetition.

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?

For a project update tool with a full input schema, an output schema, and rich annotations, the description supplies the missing behavioral context about partial updates and locale replacement. Together with the structured metadata, it is complete enough for correct invocation.

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 baseline is 3, but the description adds useful semantics by stating that fields left out keep their values and that locales replaces the whole list. Those details give the agent behavior-level understanding beyond the parameter descriptions themselves.

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 states a specific action ('rename a project or change its domain, languages, default voice or narration speed') against a named resource, making the tool's scope clear. It also explicitly separates itself from pronunciation fixes, so an agent can distinguish it from set_pronunciation_rule without opening the 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?

It gives a clear when-to-use condition and a when-not-to-use exclusion ('Not for pronunciation fixes'). It stops short of naming the alternative tool for pronunciation work, so it is clear but not fully explicit about routing alternatives.

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