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

Annotations already flag destructiveHint=true and idempotentHint=true, so the description gets credit only for what it adds: rubric validation with a problems[] rejection payload, and the promise that levers and projects are preserved across replacement. That last detail is genuinely useful side-effect information not present in 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?

Four short, front-loaded sentences with the mutation/replacement behavior stated first. The closing 'area is which of the five life areas' sentence is slightly circular but earns its place as the only parameter note.

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?

Covers the mutation semantics, failure mode, and preservation guarantees, which is solid for a 5-required-parameter write tool with no output schema. It is still thin on success behavior and on the relationship to the draft-checking sibling, so an agent lacks a full picture of the intended flow.

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 43% across 7 parameters, so the description carries a compensation burden it does not meet: it explains 'area' as one of five life areas (largely redundant with the enum and 'default money'), but says nothing about why, metric, target, baseline, or the deadline format. The remaining parameters are undocumented in both places.

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 ('Save the yearly goal, or replace it with the next one'), which distinguishes it from read-side siblings like get_goal and draft-validation via check_goal_draft. It stops short of naming those siblings explicitly, so an agent must infer the boundary from the 'yearly goal' scope.

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?

Implies usage through 'save ... or replace it with the next one' and discloses that the rubric is validated on save, but never says when to prefer check_goal_draft first or what preconditions exist. Adequate but leaves the workflow decision to inference.

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