Add a QR code placement to a campaign

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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds real value beyond them: the qr:write scope requirement and the fact that each code counts separately (a billing/quota implication). It doesn't say what happens on duplicate labels, but the additions are substantive.

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, no waste, and the core action is front-loaded before the counting constraint and permission note. Every sentence 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?

For a 2-parameter creation tool with annotations covering safety and no output schema, the description plus schema is nearly sufficient. The one gap is that campaignId's format (uuid) and role are left entirely to the schema, but an agent can still call it correctly.

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 50%: label is documented in the schema and the description reinforces it with a placement example ('Poster, main hall'), while campaignId is only implied by 'to a campaign'. With half the parameters covered by structured fields, this lands at baseline rather than above it.

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: 'Add one printable code to a campaign', which clearly distinguishes adding a code from creating a campaign (create_qr_campaign). The label example further pins down what a 'code' is here. It doesn't name a sibling explicitly, but the resource is unambiguous.

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?

'Each code is counted separately' implicitly tells the agent to call once per placement rather than batch, and 'Needs qr:write' signals the permission prerequisite. However, it never states when to choose this over create_qr_campaign or update_qr_campaign, leaving the routing to inference from the names.

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