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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description goes beyond them by disclosing the credit behavior for the unused part of an existing term and that FLUX is quoted at market rate. It does not mention that the schema exposes private-key parameters, but for a read-only quote this is a minor gap.

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?

Two sentences, front-loaded with the action and result, with the update/credit parenthetical kept tight. No filler.

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?

No output schema exists, and the description does explain the return content (USD plus FLUX at market rate), which is the critical piece for a quote tool. It is nearly complete, though it leaves the role of the private-key parameters unexplained.

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 67%, so the schema already documents key parameters (owner, expire, fluxIdPrivateKey, paymentPrivateKey). The description adds only the abstract notion of 'the given specification' and does not add meaning for the key params or the spec fields. Baseline 3 for a partly-covered schema with no added parameter detail.

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+resource: 'Returns the Flux Cloud price for registering the given specification, or for updating it if an app of that name already exists.' This clearly distinguishes a pricing/quote operation from deployment siblings. It does not explicitly name alternatives like flux_deploy_app or flux_get_pricing, but the purpose is unambiguous.

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?

Usage is implied (get a price before deploying) rather than stated. It does explain the register-vs-update branch cleanly, which is helpful context, but there are no explicit when-to-use/when-not conditions or named alternatives such as flux_get_pricing vs flux_deploy_app.

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