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

With no annotations, the description carries the transparency burden and does substantive work: it warns that null is rejected脚下的 and explains why 'unchanged' and 'cleared' must not look the same. It also discloses that task state is not editable. It stops short of saying what the call returns or whether updates are idempotent, but the key behavioral traps are surfaced.

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 three sentences with no filler. It front-loads the action, then explains the null/unchanged contract, then routes state changes to the correct siblings. Every sentence earns its place and none merely repeats schema content.

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 an 8-parameter update tool with no annotations and no output schema, the description plus the richly described schema covers the invocation essentials: update semantics, null behavior, and sibling routing. The two notable gaps are the missing response shape and the prose omitting `name` from the editable-field list, but these are minor relative to the overall guidance provided.

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%, so the baseline is 3; the schema already documents all eight parameters. The description adds meaningful semantic value by explaining the omit-to-leave-unchanged rule and the null prohibition, which materially affects how an agent should construct parameters. It does not add per-parameter detail, but it compensates where the schema is silent about update behavior.

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 clear action and resource: 'Change the schedule, destination, method, timeout, headers or body of an existing task.' It also distinguishes itself from state-focused siblings by saying 'State is NOT editable here.' However, the prose list of editable fields omits the `name` parameter that the schema exposes, so the description is not a fully complete statement of what can be changed.

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 explains the partial-update usage contract: 'Omit a field to leave it unchanged — sending null is refused.' It also gives a clear when-not-to-use instruction by naming alternatives: 'State is NOT editable here: use pause_task and resume_task.' This makes the choice between update_task and state-control siblings explicit.

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