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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description is free to add the genuinely useful behavior: that the brief includes PENDING agent prompts outstanding before the task can start, and that it deliberately returns a scoped subset rather than the full record. It does not discuss failure modes for a missing/invalid taskId, which keeps it from a 5.

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?

Two dense sentences with zero filler; the payload list is front-loaded and the sibling relationships come second. Every clause either defines the return or positions the tool against its alternatives.

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?

With no output schema, the description takes on the job of describing the return shape and does so field by field, including the non-obvious pending-agent-prompts element. Combined with the annotations covering safety, an agent has everything needed to select and call this tool correctly.

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?

There is one parameter and schema description coverage is 100% ('The task you want the brief for.'), so the schema already carries the semantics. The description only implies a single-task scope, adding no format, ID-shape, or source-of-ID detail. Baseline 3 applies when the schema does the heavy lifting.

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 ('Return the focused brief for a single task') and enumerates the exact payload (title, description, agentBrief, collaborators, parent, dependencies, project context, pending prompts). It also explicitly contrasts itself with get_task, so an agent can distinguish it from the closest sibling without opening either schema.

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?

Gives clear usage context: this is what to read 'to begin work' rather than the full task record, and it names two alternatives (get_task and list_assigned_tasks, the latter supplying the queue). It stops short of an explicit 'do not use this when...' rule, but the contrast with get_task is sufficient to route the agent.

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