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

Beyond the annotations, which already declare a non-read-only, non-destructive, idempotent, closed-world write, the description discloses the key behavioral facts an agent needs: no charge occurs, and the reply carries a message plus usually a link (Stripe checkout or sign-in) or a waitlist notice. It does not discuss what happens on repeated calls or bad input, but the idempotency annotation covers part of that.

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 with the consent precondition front-loaded right after the action, and the return behavior last. There is no filler or repetition.

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 7-parameter write tool with full schema coverage and no output schema, the description adequately covers the action, precondition and expected reply. Minor gaps remain around repeat-call behavior and error cases, but nothing critical for correct invocation 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?

Schema description coverage is 100%, so the schema already explains plan, email, company, website, industry, keep_up_with and person_agreed. The description only reinforces the work-email and consent requirements, which are already encoded as format and const constraints, so it adds little new meaning.

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 a specific verb and resource: it starts a signup ("Starts nwsppr") for the person's company, which the title confirms as a signup action. The product name 'nwsppr' is opaque without outside knowledge, but the action is clear enough to distinguish it from the sibling tools list_plans and todays_top_stories, which are read-only lookups.

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 gives an explicit precondition: call only after the person asked for or agreed to the signup, and use their own work email. That is a clear when-to-call rule plus a constraint on the input, and no sibling tool competes for this use case, so no alternative routing is needed.

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