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

Annotations cover the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), and the description adds real value beyond them: it never overwrites an existing score, free accounts are capped at 3 scores, and the account must be linked. That is substantive non-obvious behavior, though failure modes (what happens at the 3-score cap) are left unstated.

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?

A single front-loaded sentence where each clause carries information (NEW, non-overwrite, free-tier cap, title default, account requirement). The stacked parentheticals make it slightly dense but nothing is wasted.

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 an output schema present it needn't describe return values, and annotations carry the idempotency/destructiveness profile. The prerequisite and creation semantics are covered, leaving only the cap-overflow behavior and sibling disambiguation as gaps.

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 100%, so both parameters are already documented. The description adds that the title defaults to the score's own title, which slightly reinforces the schema default, but no extra syntax or provenance detail is added beyond it.

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 draft as a NEW score in the linked account's library') and clarifies the non-overwriting semantics. It never names the sibling create_score, so the agent must guess which creation path applies, which keeps it short of a 5.

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?

It gives one clear prerequisite ('Needs the account linked') and implies the draft-from-a-previous-tool workflow, but offers no explicit when-to-use versus create_score, import_score, or update_my_score. Usage is inferable rather than stated.

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