validate_card_project

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the non-mutating nature is covered. The description adds value beyond that by disclosing the categories of problems returned (text-fit, image, guest-addressing), which is the key behavioral trait of a validator with no output schema.

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 clauses — what it does and when to use it — with zero filler. The purpose is front-loaded ahead of the timing guidance.

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 read-only, single-parameter validator with no output schema, the description supplies enough: it says what is validated and what kinds of errors surface. It leaves minor gaps, such as whether validation is exhaustive or whether a failure blocks order placement, but nothing essential to invoking it is missing.

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?

There is a single parameter, and the schema documents it at 100% coverage, including its provenance ('Project UUID from list_card_projects'). The description adds no further parameter meaning, 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?

Specific verb (validate) plus resource (invitation project), with the output scope named: text-fit, image, and guest-addressing errors per customization. This cleanly distinguishes it from read-oriented siblings like get_card_project or preview_card_template.

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?

'Use before placing an order' gives a clear triggering condition. It does not name an alternative tool or state when validation can be skipped, so it stops short of full when/when-not guidance.

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