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

Annotations already declare non-readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuinely new context beyond that: the values propagate account-wide ('Every agent on the account reads them through get_benchmark') and are user-reversible via Settings, which tells the agent the write is persistent but not final.

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-loads the core action and keeps the value definitions tight, but it is a single long run-on sentence with stacked clauses ('so no agent asks again, and the user can change them in Settings') that would read better split. Nothing is wasted, but structure could be cleaner.

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?

Output schema exists, so return values need not be described. For a two-param, zero-required mutation with annotations covering safety, the description supplies the missing pieces: per-value meaning, single-vs-both invocation, account-wide persistence, and user-revocability. Nothing an agent needs to call it correctly is absent.

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 0% and the schema only supplies bare enums, so the description carries the load by defining each value: best as the strongest model, balanced as strong-for-fraction-of-price, cheapest as drafts and volume. That is the exact semantic gap the schema leaves, and it is fully filled.

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?

States a specific verb and resource ('Save ... model priorities') and immediately scopes it to the two knobs, image_priority and clip_priority, defining what each value means. It also names the read-side sibling get_benchmark, so an agent can place it against alternatives in the tool list.

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?

Gives concrete invocation guidance: 'Pass the one the user just answered, or both when they answered both,' which is exactly the partial-update decision an agent faces with two optional params. It does not explicitly cover what to do when the user answered neither, a small gap.

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