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

Annotations only say this is a non-read-only, non-idempotent, non-destructive write. The description adds the critical fact that it is a FULL REPLACE of three fields (so unstated values are overwritten), that every fleet, cluster and namespace figure re-prices on its next read, and that it is reversible by restoring the previous values. That is exactly the extra context annotations cannot carry, and nothing contradicts the hints.

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 replace semantics before the optional parameter and the permission/reversibility notes, which is the right ordering. It is slightly dense with parenthetical enumerations and could trim the duplicated min/max/default restatement of analysed_cluster_limit, which the schema already provides.

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?

With no output schema and a destructive-adjacent plain write, the description supplies everything an agent needs: required vs optional params, permission gate, global re-pricing side effect, and the reversal path. Nothing material about invoking it correctly is left unstated.

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 goes beyond the schema by explaining the replace-vs-optional asymmetry: the three pricing fields must be restated wholesale while analysed_cluster_limit is optional and keeping the current limit when omitted. This is meaningful semantic guidance not derivable from the property descriptions alone.

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 (Replace) and resource (the organisation's cloud cost pricing settings) and enumerates the exact fields mutated: currency, effective discount, egress estimate, and analysed_cluster_limit. This separates it cleanly from the read-side sibling get_cost_settings and from unrelated cost tools like set_cost_budget and update_cost_autopilot.

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 an explicit prerequisite and procedure (call get_cost_settings first and restate every value, changing only what the user asked for), names the permission required (organisation admins, billing.manage), and states the omitted-parameter behaviour for the optional field. The only thing absent is a named alternative to use instead, which is barely relevant for a settings writer.

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