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

Annotations only tell the agent this is a non-read-only, destructive write. The description goes well beyond: it discloses the partial-save scope (other v1/v2 fields untouched), the silent-ignore protection on the 'Main' crypto entry, the breadth of what Currency definitions control, and downstream references (item prices, SKUs, rewards). That is substantive behavioral context an agent cannot get from the structured fields.

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?

Front-loaded with the most decision-relevant constraint ('PARTIAL SAVE'), then progressively narrower detail, ending on the protected-key warning. Dense but each sentence carries information; only the catalogue enumeration is arguably expendable.

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 deeply nested, no-output-schema mutation tool, the description covers purpose, side effects, and a critical exception. It leaves one notable gap for a destructive write: whether the supplied Currency object replaces the entire collection (implicitly deleting omitted currencies) and any permission/auth prerequisites are not stated.

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. The description adds meaningful semantic framing for the `value` payload by enumerating what currency entries define (IDs, USD economy, recharge/conversion rules, permissions) and their cross-entity reference role, going slightly beyond the schema's per-field text.

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?

Opens with a specific verb+resource+scope: 'PARTIAL SAVE: writes ONLY the Currency field of TitlePublicConfigurationModel'. This immediately distinguishes it from the many other save_* siblings and from get_currency, which the agent can act on 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 clear context on when this applies (currency catalogue, economy, recharge, conversion, permissions) and an important when-not: the 'Main' CryptoCurrency entry cannot be overwritten. It does not explicitly route to a sibling (e.g. read via get_currency first), so it falls short of full when/when-not/alternatives guidance.

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