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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description reinforces this with "opens nothing by itself," removing any ambiguity about side effects. It also adds genuinely non-obvious context not in the annotations: that no public Partiful API exists, so browser automation is required, and that the payload is step-by-step screen/button/field instructions.

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?

The core capability and the no-side-effect caveat are front-loaded in the first clause, which is the right structure. The final sentence ("Partiful's official API: Partiful has no public API and no developer docs") is slightly redundant in its own phrasing, and the hard-coded check date adds noise without much value.

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 zero-parameter, no-output-schema tool the description covers what an agent needs: what comes back (step-by-step instructions), that nothing is opened, and which tool family performs the actual work. It could note the return shape more concretely (plain text vs structured steps), but the essentials are present.

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?

The tool takes zero parameters, so there is no parameter meaning for the description to add and the baseline of 4 applies. Nothing in the description misleads about inputs.

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?

"Export guest list in the user's own Partiful account" gives a specific verb and resource, and the follow-on sentence clarifies that the tool returns instructions rather than performing the export. It does not distinguish itself from sibling partiful_list_rsvps, which an agent could easily confuse with a guest-list read, so it falls short of a 5.

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?

The description lays out the intended workflow explicitly: this tool returns the steps, then the agent executes them with the cotlet_browser_* tools in the Partiful Cloud Browser. That is clear sequencing guidance, though it never states when to prefer partiful_list_rsvps or the other Partiful siblings instead, so no true exclusion is given.

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