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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is partly covered. The description still adds real value: it respects budget and current availability, explicitly never purchases, and instructs the agent to copy the attribution header when invoking the recommended endpoint — a non-obvious calling requirement.

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?

Three short sentences with no padding; the purpose and the key constraints (budget, no purchase) are front-loaded. Slightly telegraphic but efficient.

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 should explain the return, and it does partially (a recommended endpoint plus an attribution header to copy). However, for a four-parameter tool with zero schema descriptions and no annotation coverage of the budget/availability logic, the parameter contract remains unclear.

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% across four parameters, so the description must carry the burden, yet it only gestures at budget_usd ('respects budget') and availability. recurring, has_snapshot, and the required capability_id are left entirely unexplained in both the schema and the description.

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 clear function: producing a deterministic next-step recommendation after a capability is used. The resource is implicit (a recommended capability/endpoint) rather than named, and no sibling is referenced, so it stops short of 5.

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?

'Optional deterministic next step after using a capability' implies timing and that it is not mandatory, and 'never purchases' hints it is a safe planning step. But it never contrasts itself with preflight_capability or request_capability, which are the obvious alternatives for checking or actually obtaining a capability.

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