todo_update

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

Annotations already declare destructiveHint=true, idempotentHint=false, and readOnlyHint=false, so the safety profile is covered. The description usefully adds that omitted fields are preserved (partial update, not full replace) and that it returns a slim receipt, but does not explain what 'destructive' entails here — e.g., whether passing empty values clears fields.

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?

Three short front-loaded sentences with no filler. "Returns a slim receipt" is slightly redundant since an output schema exists, but it is cheap and does no harm.

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 mutation tool with annotations and an output schema, the safety and return concerns are largely handled elsewhere. Still, the undocumented parameters and the unstated meaning of its destructive hint leave the definition thinner than the tool's complexity warrants.

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 only 25% — six of eight parameters (body, tags, title, status, priority, todo_id) carry no schema description, and the tool description adds no per-parameter meaning at all. It fails to compensate for the low coverage.

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 (update todo fields), which is clear on its own. However, it offers no differentiation from sibling mutators like todo_complete, todo_block, or todo_archive, so an agent can't tell from the description why it would pick this over those.

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?

"Omitted fields are preserved" conveys partial-update semantics, which implies when the tool is appropriate (patch-style edits). But it never states when to prefer it over todo_complete/todo_archive for terminal states, nor any prerequisites, leaving routing to inference.

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