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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds value beyond the schema by declaring the output is informational with website links and by naming the actions it will refuse to perform, which helps the agent avoid misusing it for transactions.

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?

A single dense sentence packs the scope and the boundary list; the boundary clause is appropriately front-loaded within it. It is slightly overloaded (four topics plus four prohibitions in one breath) but every clause earns its place.

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 parameters, no output schema, and full annotation coverage, the description only needs to establish scope and safe-use boundaries, which it does by listing covered topics and forbidden actions. Return content (website links) is hinted at, which is adequate for an informational tool.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. Nothing in the text contradicts the schema.

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?

The description uses a specific verb ('Explain') and enumerates the exact subject matter: free samples, weekly Plus service, the current CAD subscription offer, and the separate authenticated member MCP setup. That is far more concrete than a tautology, though it never explicitly contrasts itself with the recipe siblings.

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?

It defines the usage context (questions about offerings, pricing, and MCP setup) and, unusually, states explicit exclusions: it cannot subscribe, change an account, send groceries, or pay. No alternative tool is named, but the siblings (recipe lookup) do not compete with this scope.

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