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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds the returned field set and the cross-entity relationship (postcard templates), which is useful, but says nothing about ordering, pagination, or behavior for a user with no QR codes.

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?

Two compact sentences: the first front-loads what is returned, the second gives the follow-up actions. Every clause carries information and nothing is redundant.

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 responsibly enumerates the salient return fields and neighbor tools, which is enough for a zero-param read. Only minor gaps remain (result ordering, empty-list behavior), which are low-risk for this 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 the baseline is 4; there is no parameter semantics for the description to compensate for, and it does not waste space restating schema content.

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 states the resource (the user's tracked QR codes) and enumerates what each record contains: destination URL, colors, and which postcard templates print it. The listing verb comes from the name/title rather than the description, but the scope is unambiguous and clearly distinct from spur_get_qr_code_activity (scans) and spur_create_qr_code.

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 routes the agent to two explicit alternatives with their conditions: use spur_add_postcard_qr_code to attach a code to a postcard, and spur_get_qr_code_activity for scan data. It does not spell out an explicit 'use this when you need an inventory of codes' statement, but the implied context is strong.

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