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

Goes well beyond the annotations by disclosing the Pro requirement, the exact-name matching constraint, the first-match-only behavior on duplicate names, and the returned id/name used to confirm which task was completed. What it omits is whether completion is reversible or how a no-match is reported, which matters given destructiveHint=true.

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?

Four short sentences, front-loaded with the action and prerequisite, then the input preference, then the ambiguity rule. The final sentence restates a return value that an output schema already covers, but the rest is dense with useful content.

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 destructive single-target mutation this covers prerequisites, identifier sourcing, ambiguity resolution and post-call confirmation. The remaining gap is failure behavior (no matching name) and reversibility, which an output schema alone cannot convey.

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 coverage is already 100%, so a 3 is the baseline, but the description adds real decision semantics: prefer task_id, task_name must match exactly, and ties resolve to the first match. Only the vestigial `confirm` parameter is left unaddressed, though the schema itself already explains it.

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 ('Marks an OmniFocus task as complete') and names the OmniFocus family, which separates it from the sibling complete_reminder, todoist_complete_task and todo_complete_task without ambiguity.

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 the prerequisite (OmniFocus Pro), the preferred path (task_id from list_omnifocus_tasks or search_omnifocus_tasks) and the fallback condition with its exact-match rule. The agent knows both when to use it and how to choose between the two input modes.

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