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

Adds real value beyond annotations: the draft lifecycle, the deferred charging, the handoff to submit_job, and the return value (job id). It does not address non-idempotency (duplicate calls create duplicate drafts) or authentication, which the annotations only flag indirectly via idempotentHint=false.

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?

Front-loaded 'WRITE:' marker, then scope, safety behavior, prerequisite, and return value in four short sentences with zero filler. The trailing POST endpoint is minor but harmless orientation.

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 15-parameter, 9-required creation tool with no output schema, the description covers intent, side-effect posture, prerequisite lookup, and return value. Gaps are minor: no mention of validation failure behavior or what happens to draft jobs left unsent.

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, but the description adds actionable meaning the schema cannot: the option-valued parameters must match strings from click2mail_get_product_options, which matters because the schema has zero enums. It doesn't clarify which parameters are immutable after creation.

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 ('create a mailing job from an uploaded document and an address list') and pairs it with the crucial qualifier that the result is a draft, which cleanly separates it from click2mail_submit_job. An agent can route to it without opening a sibling schema.

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?

Explicitly says the job stays in Editing status and nothing is printed, mailed, or charged until click2mail_submit_job, and directs the agent to pull exact option strings from click2mail_get_product_options. Both the when-to-use and the when-not are stated.

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