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

Annotations already declare readOnly=true, destructive=false and openWorld=false, but the description adds meaningful behavioral context beyond them: results are scoped to the authenticated store, Wix/Shopify data appears only when a server-side link is configured, and knowledge is limited to this MCP's own attempts. The caveats about interpreting empty results and not creating duplicate labels are exactly the kind of operational nuance annotations cannot convey.

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?

Four short sentences, front-loaded with the primary lookup behavior and followed by important constraints. Every sentence carries actionable information; none is filler or tautological.

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 annotations covering safety and no output schema, the description still explains lookup modes, scoping constraints and interpretation caveats. It does not describe what an attempt record contains or how results are formatted, which is a minor gap for a diagnostic listing tool but not enough to prevent correct invocation.

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 schema already documents all four parameters, including the default of listing 10 recent attempts when supportCode is omitted and that instanceId is ignored server-side. The description reinforces source and orderId usage but adds little syntax or format detail beyond the schema, 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?

States a specific verb and resource: querying label-issuance attempts for the authenticated store, either by support code or by listing the 10 most recent. It distinguishes itself from generate_label and recover_label_pdf through the explicit warning not to create another label, though it does not name the sibling tools directly.

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?

Gives clear operational routing: use supportCode to look up by service code, otherwise list up to 10 recent attempts, and use source plus orderId for Wix/Shopify. It also states when not to act — do not interpret an absent record as an absent issuance and do not create another label to fix a pending PDF — which explicitly steers agents away from generate_label and related siblings.

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