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

Annotations already declare read-only, idempotent, open-world and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral facts: data is read live from the catalog at call time (freshness), and no account, wallet or payment is required (auth/prerequisite). It says nothing about pagination or result size, but an output schema exists.

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 core purpose is front-loaded in the first sentence, followed by short operational sentences that each carry information. The opening sentence is dense and stacks several clauses (hardware, per-plan specs, hour blocks, payment network), but nothing is redundant padding.

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 one-parameter read tool with full annotations and an output schema, the description covers what the tool returns conceptually, the payment/auth model and data freshness without needing to describe return shapes. The only meaningful omission is sibling routing relative to compute_quote.

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% and the single `plan` parameter is already documented in the schema with the same omit-for-all semantics. The description's 'Pass `plan` to read one plan' restates the schema rather than adding format, id conventions or error behavior, so the baseline 3 applies.

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?

Specific verb and resource: 'Lists the confidential virtual machines ... Agentgates rents to agents by the hour', with the per-plan fields (vCPU, memory, disk, traffic) and pricing model spelled out. It is clearly a catalog-listing tool, but it never names compute_quote or compute_docs, so the boundary with the siblings is left to inference.

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?

'Pass `plan` to read one plan' and 'Omit for every plan on sale' cover how to narrow the call, and 'Free: no account, no wallet, no payment' signals it is safe to call speculatively. However, there is no statement of when to use this versus compute_quote (the obvious listing-vs-pricing routing decision), so usage is implied rather than prescribed.

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