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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=false, so safety is covered. The description adds genuinely useful context beyond them: the write is field-scoped and leaves other v1/v2 fields untouched, the section contains no secrets by protocol design, and multiple per-platform audiences are accepted. It does not disclose permission requirements or the fact that the existing Authentication block itself is replaced wholesale when written.

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 critical constraint ('PARTIAL SAVE') is front-loaded in the first clause, and the following sentences each add a distinct fact rather than restating the schema. It is somewhat dense and overlaps with nested-schema text, but no sentence is wasted.

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 nested-object write with 100% schema coverage and no output schema, the description covers the essentials: scope of the write, absence of secrets, and per-platform audience behaviour. It stops short of stating permission requirements, whether the Authentication block is fully replaced, and what the caller receives on success.

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, but the description adds semantics the schema alone does not organize: the ID-token audience differs per platform (web/Android tokens carry the Web client ID, iOS tokens the iOS client ID) so several IDs should be filled at once and the server accepts any of them. This synthesis helps the agent populate the nested value object correctly.

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 verb and resource and immediately scopes it: 'PARTIAL SAVE: writes ONLY the Authentication field of TitlePublicConfigurationModel; all other v1/v2 fields stay untouched.' This distinguishes it from get_authentication and from the many save_* siblings, and it enumerates what the Authentication field actually contains.

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 strong context about what belongs in the payload (public OAuth client IDs only, no secrets; device/e-mail/Telegram/SSO logins need no configuration), which implicitly tells the agent when a call is warranted. However, it never states an explicit when-to-use or when-not-to-use condition, nor does it recommend the read-then-write pattern via get_authentication. Usage guidance is implied rather than stated.

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