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

Annotations already declare destructiveHint=false and openWorldHint=true, but the description adds substantial extra context: it only changes passed fields while leaving the rest untouched, it sends no confirmation itself, the change is reversible via another call, and it requires a Cotlet API key with access to this app. That is well beyond what the annotations 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 and efficiently stacked with behavioral facts and preconditions in a few sentences. The redundant 'Partiful:' prefix mirrors the title, a minor waste, but no sentence is filler.

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 2-param mutation tool with no output schema, the description covers the mutation semantics, reversibility, lack of side-effecting confirmation, precondition (get_event), and auth requirement. An agent has everything needed to invoke it correctly.

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 both parameters are already documented with their allowed fields and source (event_id from list_events). The description adds no per-parameter detail beyond the generic 'fields you pass', so baseline 3 is appropriate.

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 ('Change the details or settings of an event you host'), and the 'you host' scope narrows it usefully. It does not explicitly distinguish itself from siblings like partiful_cancel_event or partiful_duplicate_event, but the updatable-field framing makes the intent unambiguous.

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?

Provides explicit workflow guidance ('Use get_event first to see the current values') and notes partial-update semantics. It does not name when NOT to use it or point to alternative siblings, keeping it below a 5.

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