update_todo

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

Discloses partial update semantics, tag replacement, idempotence, and error handling ('Errors if the id does not exist'). No annotations provided, so description carries full burden.

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?

Concise three-sentence description plus example. Front-loaded key behavior, no redundant 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?

Given no output schema, the description covers all needed aspects: side effects, error handling, usage guidance, and parameter behavior. No gaps.

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 100% and descriptions are clear. The description adds value by summarizing partial update behavior, clarifying tag replacement, and providing an example, which aids understanding beyond schema.

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?

Description clearly states 'Update an existing todo's fields' and distinguishes from siblings mark_todo_done/reopen_todo by specifying when to use each.

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?

Explicitly states when to use update_todo vs alternatives ('prefer mark_todo_done / reopen_todo for clearer intent'), describes partial update behavior, idempotence, and error condition.

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