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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description reinforces this with 'calling again for the same date corrects it' plus the side effect that a milestone reaching its target becomes done. That side-effect disclosure is genuine added value beyond the annotation set.

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?

Three sentences, front-loaded with the core action, then examples, then the per-date correction rule and target-reached behavior. Dense but every clause carries information; nothing is filler.

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 small mutation tool with no output schema, the description covers what the value means, the per-date overwrite rule, and the milestone completion side effect. Return format is only hinted at ('Says when the target is reached'), which is a minor residual 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?

Schema coverage is 67% (value has no schema description), but the description compensates by defining value semantics ('1 marks it done' for done-or-not goals) and clarifying that milestoneId targets a countable milestone rather than the goal. This adds meaning the schema alone does not convey.

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 (record) and resource (the goal metric value, or a countable milestone when milestoneId is given), with concrete examples that make the intent unmistakable. It is clearly distinguishable from sibling setters like set_goal or edit_milestone.

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?

Explains when to pass milestoneId versus recording the goal metric, gives example phrasings, and clarifies the 'one value per date, call again to correct' convention. It stops short of naming an alternative tool or stating exclusions, but the usage context is clear.

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