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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description adds real behavioral value beyond them: it discloses atomic validation ('every measure must read and fill its time signature, or nothing is created') and that refusals name each fault with its location, which is exactly the kind of failure semantics an agent needs before calling. It does not cover auth or overwrite behavior, keeping it out of 5 territory.

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?

The format spec genuinely needs space, and the first sentence front-loads purpose plus an example. However it is an unstructured wall of prose with redundancy ('strings from 1 (the highest)' appears twice, the time-signature rule is stated twice, and uppercase emphasis substitutes for structure) that bulleting would have made far easier to parse.

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 domain as complex as a bespoke music-notation language, the description supplies grammar, edge rules, worked examples, and a link to the full format, and an output schema exists so return values need not be explained. Nothing material is missing for correct invocation.

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?

Although the single parameter has 100% schema description coverage, that coverage is a tautology ('the score... in the notation described above'). The description carries the entire grammar of the .cesure value – beat syntax, durations, note/beat props, time-signature filling rules, and worked examples – which is indispensable for supplying a valid value.

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?

The opening states a specific verb and resource ('Create a score you write as a .cesure') plus the resulting side effect ('open it as a draft'), so an agent immediately knows what gets produced. It stops short of distinguishing itself from close siblings like save_new_score or import_score, which are the tools an agent would most likely confuse it with.

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?

Usage is only implied: 'open it as a draft' hints that this creates without committing, which contrasts with save_new_score, but no sentence states when to prefer this tool over import_score or save_new_score. The agent must infer the routing from sibling names.

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