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

Goes well beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true): it discloses that no invites/emails are sent, that the signup becomes visible to anyone with the link, that each call is user-confirmed by default with an opt-out, and that it reaches other people and needs a scoped API key. That is exactly the extra behavioral context annotations cannot convey.

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 with the core action, but the public-link concept is stated three times ('return its public link', 'visible to anyone with the link and returns that link') and the invite/email exclusion is repeated in two consecutive sentences. Tighter phrasing would preserve all the information.

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 one-parameter, no-output-schema tool, the description covers the mutation effect, the visibility consequence, the return value (public link), the confirmation requirement, and the auth prerequisite. Nothing an agent needs to call it safely 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?

With schema description coverage at 100%, the schema already documents signup_id ('Sign-up ID from list_signups'). The description adds no syntax, format, or sourcing detail for the parameter, 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?

States a specific verb and resource ('Make a draft sign-up live') plus the observable result ('return its public link'). It also explicitly distinguishes the operation from send_message, so an agent can separate publish from notify without inspecting either 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?

Gives explicit when-not guidance ('Does not send invites', 'does not email the group; use send_message for that') and a precondition (Cotlet API key with access to the app). It stops short of enumerating broader siblings like create_signup or duplicate_signup, but the key alternative is named.

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