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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false): partial-update semantics, the deadline, uncertainty about guest notification ('Evite does not say whether guests are told'), the external reach warning, and the default confirmation behavior plus the Cotlet API key requirement. This is unusually rich behavioral disclosure for a mutation tool.

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?

Dense and front-loaded, leading with the core action and partial-update rule before the caveats. Some clauses are run-on and slightly repetitive, but nearly every sentence carries actionable 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 2-param mutation with no output schema, the description covers the important behavioral context (deadline, partial updates, confirmation, auth). It doesn't mention the return/response shape, but with no output schema that omission is minor.

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 documents event_id and fields. The description's field list mirrors what the schema provides and adds no format or syntax detail beyond it, 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 ('Change event details') and resource (event), and immediately clarifies the partial-update semantics ('Only the fields you pass change'). It enumerates the editable fields and explicitly separates the design text, so an agent can distinguish this from other Evite write tools.

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 clear context for use: which fields, the constraint that edits are allowed only 'until the event date', and the warning that design text must be kept in step separately. It stops short of naming an explicit sibling alternative for the design-text case, so it's a 4 rather than a 5.

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