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

The description discloses behaviors such as the need for confirmation for delete_all, that deletions are recoverable (soft-delete), and that list actions need proper timezone to avoid misleading due dates. This adds transparency beyond the annotations (readOnlyHint=false, destructiveHint=true) by clarifying the nature of deletion and listing behavior. However, it doesn't mention idempotency or other potential edge cases, but given annotations and schema, this is sufficient.

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 compact but covers essential points: the actions, the timezone requirement for list, and the confirmation for delete_all. It is front-loaded with the verb (Create, update...). However, it could be slightly more organized by separating the different action-specific guidance, but it's acceptably concise.

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 the complexity (22 params, 5 actions) and the presence of output schema, the description covers the most critical usage scenarios: it highlights timezone for list, confirmation for delete_all, and that delete is soft/recoverable. It doesn't explain returns or all actions in detail, but the output schema and the schema's per-parameter descriptions cover much. The description adds essential context for the less obvious aspects, making it fairly complete.

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?

The schema has 100% description coverage for parameters, so the baseline is 3. The description adds value by explaining the purpose of `owner_timezone` (honest due dates) and `confirm_delete_all` (explicit confirmation for delete_all). It also hints at relationships between action and required params via conditional schema. The description goes beyond the schema by explaining the context for these parameters, so a 4 is warranted.

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 states the tool performs 'Create, update, complete, list, or bulk soft-delete authorized TODOs' with specific verbs and resources. It clearly covers the main actions and differentiates from siblings like open_todo_board or ledger by focusing on CRUD operations for TODOs.

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?

Provides explicit guidance: for action='list' it instructs to provide the user's real IANA owner_timezone or use a saved owner profile timezone to ensure honest due dates. It also specifies that delete_all should only be used after explicit user confirmation and requires confirm_delete_all=true. These are clear usage directives beyond what the schema states.

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