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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so safety is covered. The description adds useful defaults (date=today, horizon=month) but says nothing about duplicate handling, permissions, or response behavior.

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 sentences, zero filler, with the core action and defaults front-loaded and the sibling routing placed at the end where it belongs.

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 7-parameter mutation tool with no output schema and 57% schema coverage, the description supplies defaults, the star/subgoal/after semantics, and the alternative tool. Only the sphere parameter and return behavior remain unaddressed, which is a minor gap.

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?

With 57% schema coverage, the description compensates by explaining several parameters semantically: date defaults to today, horizon defaults to month, 'star' maps to the important flag, 'subgoals', and 'the goals it comes after' maps to the after array. Only sphere is left unexplained.

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 (add) and resource (one goal), and scopes it precisely to the month/quarter/year period containing date. It explicitly contrasts itself with the sibling build_goal_flow, so an agent can distinguish the two 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?

Names the alternative (build_goal_flow) and the condition that selects it ('for a whole path to a bigger goal'), and clarifies the default behaviors (date=today when omitted, horizon=month). It gives clear context but doesn't address other siblings like update_goal or delete_goal.

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