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

Annotations indicate readOnlyHint=false and destructiveHint=false. The description adds meaningful behavioral context by emphasizing the confirmation requirement ('Requires confirm=true'), which is a guardrail not captured by annotations. It also discloses the dual identification method. The preview behavior is left to the schema but the confirmation requirement is highlighted.

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 description is two short sentences with no filler. It front-loads the verb and resource ('Marks an OmniFocus task as complete') and immediately follows with the critical confirmation constraint. Every word earns its place.

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?

The description covers the essential aspects: purpose, identification method, and the confirmation requirement. An output schema exists, so return values need not be described. It does not explicitly explain the preview behavior, but that is captured in the schema's confirm parameter, and the tool's simplicity makes this adequate.

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 baseline is 3. The description repeats the ID/name OR relationship and the confirm requirement without adding new meaning beyond what the schema already provides. It succinctly summarizes but does not improve upon the parameter documentation.

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 clearly states the action (marks as complete) and the specific resource (OmniFocus task), distinguishing it from sibling tools like create_omnifocus_task, complete_reminder, and todoist_complete_task. The phrase 'by task ID or name' further specifies the scope of operation.

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 provides clear context for when to use the tool (completing an OmniFocus task) and how to identify the target (by ID or name). However, it does not explicitly mention alternatives or situations where another tool should be used, pulling back from a 5.

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