Complete todo

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

The description does not contradict the annotations and is consistent with them: readOnlyHint=false and destructiveHint=false indicate a mutating but non-destructive operation, and idempotentHint=true suggests repeating the call is safe. However, the description itself adds little behavioral context beyond the annotations, such as what happens if the id does not exist or whether the operation is reversible.

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 a single concise sentence that is front-loaded with the operation first and the required parameter mode at the end. Every word earns its place, and no unnecessary information is repeated from the schema or annotations.

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 tool is simple, has only one required parameter, an output schema, and annotations covering idempotency and destructiveness. The description plus structured data provide enough context for an agent to select and invoke the tool correctly without needing further explanatory prose.

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 0%, but there is only one parameter, and the description compensates by identifying id as the todo item identifier to mark done. This adds meaning beyond the schema's bare field title 'Id,' which alone does not indicate how the id is used in the operation.

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 uses a specific verb and resource: 'Mark one todo item as done by id.' This clearly distinguishes the tool from the sibling tools add_todo and list_todos, which perform creation and listing rather than status mutation. The action is unambiguous and the resource is clearly scoped to a single todo item.

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 makes the intended usage context clear: use this tool when the agent needs to mark a specific existing todo as done by providing its id. It does not explicitly name when not to use it or mention alternatives, but the action is specific enough that an agent can infer when to invoke it versus adding or listing todos.

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