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

Annotations already mark destructiveHint and idempotentHint, but the description adds crucial detail beyond those signals: it explains the merge semantics (unspecified fields keep current values), the locale replacement behavior and its effect on the localization audit, and the no-op case. This gives the agent a precise mental model of the tool's side effects.

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 sentences, each carrying distinct information: what changes, how the rewrite preserves unspecified fields, and the special destructive/idempotent locale behavior. No filler or redundant wording; the key behavioral details are front-loaded.

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 an output schema exists, 7 parameters are individually documented, and annotations cover safety and idempotency, the description supplies the remaining operational semantics needed to call the tool correctly: partial update behavior, locale replacement consequences, and no-op conditions. Nothing essential is missing.

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 the baseline is 3. The description adds the important whole-record rewrite behavior, clarifying that omitted parameters are preserved rather than reset. The locale replacement note is redundant with the schema's own parameter description, but the partial-update semantics are genuinely additional value.

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 uses a specific verb ('Change') and resource ('Tutorializer project'), and enumerates the exact fields that can be modified: name, domain, locales, default voice or narration speed. This clearly distinguishes it from sibling update tools for speech, tutorial, and video, which target different resource types.

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 strong operational context ('Reads the stored project first and rewrites the whole record') that implies when to use it, but it never explicitly contrasts with create_project or get_project, nor does it state when not to use it. The intended usage is clear from context but left to inference.

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