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

Annotations establish the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), and the description adds genuinely non-obvious traits: the value is 'sealed, never shown again' and is injected as a header on every delivery and trial call, and an empty value removes the stored credential. It does not state permission/auth requirements, which would push it higher.

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 that front-load the seller context and the core effect, with the removal behavior last. Slight marketing flavor ('Sealed, never shown again') but no wasted sentences.

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 two-parameter mutation with no output schema and annotations covering safety, the description covers purpose, effect scope (every delivery/trial call), secret handling, and deletion. Missing only auth/permission requirements and any error behavior, which are minor for this shape.

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%, so the baseline is 3; the schema already documents 'value' (full header value, e.g. "Bearer sk_live_…") and 'header' (default authorization). The description adds one meaningful semantic beyond the schema: an empty value deletes the stored credential, which is not evident from the parameter descriptions alone.

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 conveys a specific action and resource: store a seller's own API/MCP key once, and PazAIr sends it as the header on every delivery and trial call. It distinguishes itself from the many order/bid/listing siblings by being about delivery-auth credential storage. The framing is conversational ('your service needs your own key?') rather than a crisp verb+resource statement, which keeps it from a 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?

Usage is implied by the conditional 'your service needs your own key (a paid API or MCP server)?' and by the removal behavior ('an empty value removes it'). However, no alternative tool is named and no prerequisites (permissions, when-not-to-use) are stated. The agent must infer when this applies.

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