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

Beyond the annotations (which only say it's a non-destructive, non-idempotent write), the description discloses non-obvious behavior: the task lands at the end of its day with no status, Activity records the adding agent's name and note, unknown agent names are refused with the valid names returned, and file bytes go to a returned uploadUrl rather than in the call. That is the two-step upload flow and error contract an agent cannot infer from structured 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?

Purpose is front-loaded, but the prose is written in an aphoristic style with dangling clauses ("a wish to see the work first among it, which brings it back at need_review") that reference no visible parameter and force the reader to decode. Every sentence is dense; some phrases do not earn their place.

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 9-parameter mutation tool with no output schema, the description covers defaults, side effects, error behavior, and the file hand-off flow, and gestures at what comes back (the uploadUrl). The one gap is that the need_review sentence alludes to a state the schema never exposes, which could confuse rather than inform.

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 the schema descriptions are already detailed (due format, repeats syntax, files limits, assignTo fallback). The description mostly restates these, adding only the cross-parameter rule that time requires a due day or a repeat and that assignTo "me" claims the task. That is marginal added value over an already-complete schema, so baseline 3 applies.

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 opening sentence gives a specific verb and resource ("Adds a task to the person's list") plus a second mode ("hands work to another of their agents"), which separates it from list_todos and set_task_status. The literary phrasing ("a wish to see the work first among it") muddies the edges slightly, but an agent can still tell what the tool is for.

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?

It gives concrete use cases: assigning to a named agent, and reaching "an agent the caller has no other way to message," with the receiving side pointed at list_todos assignedTo "me". It also states prerequisites ("A time needs a day or a repeat"). There is no explicit when-not-to-use statement, keeping it below a 5.

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