create_song

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description still adds real value by disclosing the replacement behavior and the exact fallback state when instruments/patterns are omitted (one Grand Piano, one empty pattern on bar 0). It omits that replacing a song with unsaved changes requires discard_changes=true, which the schema carries instead.

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 short sentences, front-loaded with the destructive replacement, then the construction capability, then the default outcome. Every sentence carries information; a slightly crisper ordering could have put the default-behavior note before the sales pitch, 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?

For a 12-parameter destructive constructor with no output schema, the description covers what the tool replaces and what an empty call produces, and annotations cover the destruction risk. The main remaining gap is the unsaved-changes/discard_changes interaction, which is documented only in the schema.

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 per-parameter meaning is already fully documented, including defaults, ranges and the discard_changes guard. The description only groups the parameters conceptually ('settings, instruments, patterns and an arrangement') without adding syntax or constraints beyond the schema, which matches the baseline of 3.

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 ('Replaces the open song with a new one') plus the optional one-shot construction from settings, instruments, patterns and arrangement. It does not name a sibling it is not (e.g. update_song, open_song), so differentiation is left to inference, but the destructive 'replace' framing is unambiguous.

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?

'This is the quickest way to write a song' is a weak usage cue rather than an explicit when-to-use rule. Nothing tells the agent when to prefer update_song for modifying an existing song, or open_song for loading one; usage is only implied by the destructive replacement semantics.

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