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

Annotations already establish read-only, non-destructive, closed-world behavior, and the description adds real context beyond them: it works unauthenticated against public catalog prices, returns account-specific prices when an MCP key is present, and requires the catalog:read scope. It doesn't describe error behavior for an unknown productId, but the auth/cost model it discloses is the higher-value information.

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 statement and the ID source are front-loaded in the first sentence, and the auth/key semantics come near the end where they belong. The middle sentence about GPU models, Montréal, and 'launched in minutes' is marketing-flavored and mostly non-operational, though the CAD/hourly pricing detail does earn some of its space.

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, the description steps in by naming what comes back (CAD prices, live availability) and covers both authenticated and anonymous invocation paths plus the required permission. For a one-parameter read tool that is essentially complete, with only edge-case behavior left implicit.

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 0% for the single productId parameter, so the description must carry the meaning — it does by stating where the ID comes from (gpucloud_list_products). It adds no format or length guidance, but the origin hint is enough to call the tool correctly.

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: fetches one GPU server product with CAD prices and live availability. It also names the sibling that supplies the identifier (gpucloud_list_products), so an agent can distinguish this single-product getter from the catalog listing without opening either schema.

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?

The parenthetical '(productId from gpucloud_list_products)' makes the precondition and the preceding call explicit, which is the key routing guidance for a by-ID getter. It doesn't address when to prefer gpucloud_get_stock or gpucloud_quote_server for pricing questions, so it stops short of full when/when-not coverage.

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