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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description usefully adds the paid-plan gating and the fact that deep is a single setting shared across both markets. However, it never says whether omitting live or deep leaves the other group untouched or wipes it, which is the key behavioral risk for a settings write.

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 action and its settings mapping are front-loaded, and each clause ('paid plans only', website parity) carries information. The sentence is dense but has no obvious filler; the trailing website remark is the only borderline clause.

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 mutation tool with 33% schema coverage and no output schema, the description covers the plan gate and the meaning of the two setting groups. It leaves the genuinely ambiguous points unresolved: whether asset is ignored for deep, and whether a partial payload overwrites the unmentioned group.

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 only 33%, so the description has to carry weight, and it does explain the live/deep split and that deep applies to both markets. The required 'asset' parameter's role is muddied rather than clarified: it is mandatory, yet deep supposedly ignores market, and the description's 'for one market' phrasing never reconciles that. Partial-update semantics for the two optional groups are also unstated.

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 opens with a concrete verb+resource ('Save the user's default models for one market') and then disambiguates the two settings groups, live = the four live agents and deep = the committee seats. That is specific enough to tell it apart from get_settings and the update_* siblings, though it never names get_settings explicitly as the read counterpart.

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 an explicit trigger ('when they ask to change them') and a prerequisite ('Paid plans only'), which is real routing guidance. It stops short of stating when-not-to-use or pointing at get_settings for reads, so it is clear context without full exclusion logic.

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