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

With no annotations, the description carries the full burden and does well: it discloses that the vocal is NOT rendered, that both outputs are length-matched at 0:00, and that a soundfont is only used if FluidSynth is installed (otherwise a built-in synth renders). It omits write-location/overwrite behavior and any failure modes, which keeps it short of a 5.

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 two-sentence summary is front-loaded and states the core contract before the per-parameter notes, and each parameter line is compact and earns its place. It runs long overall, but the length is driven by genuinely non-obvious parameter syntax rather than 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 file-generating tool with no output schema and no annotations, the description covers the returned artifacts, their alignment, and the external dependency (FluidSynth) plus the required follow-up step in UTAU. The main remaining gap is the undocumented half of the parameter set (tempo, style, drums, output_dir, etc.).

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 0% across 19 parameters, so the description must compensate. It richly documents lyrics (syllable/held-note syntax), chords ('|', '%', looping), key, lyric_mode (with per-mode semantics), voice_range, guide_volume, seed, and soundfont — but leaves bass, drums, style, tempo, instrument, name, intro_bars, bars_per_line, beats_per_bar, voice_dir, and output_dir entirely unexplained.

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?

Opens with a specific verb and resource ('Turn lyrics and a chord progression into a song') and names the concrete artifacts produced (.ust plus .mid/.wav backing of matching length). This implicitly distinguishes it from siblings lyrics_to_ust and render_backing, which each produce only one of those outputs.

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?

The description explains the post-generation workflow ('open the .ust in UTAU or OpenUtau with a voicebank, and import the backing .wav alongside it'), which clarifies the intended pipeline. However, it never states when to choose this tool over lyrics_to_ust or render_backing, so the alternative-selection guidance is only implied.

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

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

No annotations are provided, so the description carries the full burden, yet it discloses no behavior: no indication that it is a read-only enumeration, what the return format is, or whether results are static. It only lists categories of options.

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 compact sentence with no filler, front-loading the four option categories. It is efficient, though as a noun phrase fragment it lacks a clear subject/verb structure.

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 no output schema and no annotations, the description should at least sketch the return shape (e.g., a mapping of category to accepted values). It enumerates the categories it will return, which is adequate for the caller to know what to expect, but leaves the structure unspecified.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline is 4. The description's mention of accepted categories is the only semantic content needed for a parameterless lookup.

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 description names the option categories (instruments, accompaniment styles, lyric modes, chord qualities) but never states a verb or that it returns the accepted values. An agent can infer enumeration from the name 'list_options', but the fragment alone doesn't distinguish it as a lookup versus a mutation.

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?

No when-to-use guidance is given. It doesn't say to call this before create_song to discover valid option values, nor mention any alternative or prerequisite, leaving the agent to guess its role relative to create_song and render_backing.

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

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the key trait — a file is written and no backing audio is produced — but says nothing about where the file lands, whether existing files are overwritten, or what permissions/paths are required for a write operation with 13 parameters.

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?

Two short sentences, front-loaded with the output artifact and followed by the argument cross-reference. Nothing is padded or repeated, and the scope constraint leads.

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 13-parameter file-writing tool with no annotations and no output schema, the definition is far too thin. It never explains the parameters, the output location, or how the generated melody relates to the supplied chords and lyrics, leaving major gaps an agent would need filled.

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 0% across 13 parameters, so the schema documents names and defaults only, with no meaning for key, lyric_mode, voice_range, bars_per_line, or the rest. The description offers no per-parameter semantics and only delegates via 'same as create_song', which leaves the agent dependent on a sibling's definition.

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 artifact: write only the UTAU .ust file, melody fitted to chords. The phrase 'no backing' distinguishes it from the sibling render_backing, so the agent can separate it from at least one alternative. It stops short of explaining what a .ust file is or how this differs from create_song beyond the missing backing.

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?

'no backing' and 'Arguments are the same as create_song' imply this is the UST-only variant of create_song, which is usable routing information. However, there is no explicit when-to-use/when-not statement, no prerequisite on voice_dir or output_dir, and no guidance on choosing this over create_song.

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

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

No annotations are provided, so the description must carry behavioral burden. It usefully discloses the notation conventions (space-separated notes, '+' to continue a word, '(xN)' for held notes), but 'preview'/'show' only implicitly conveys that this is a non-mutating inspection step — no explicit statement that nothing is written.

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?

Two sentences, front-loaded with the purpose before the notation details. Every clause carries information; the only minor nit is that the notation rules describe output rather than the tool's own behavior.

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?

An output schema exists, so return-value structure need not be re-explained, and the notation gloss helps interpret it. However, with no annotations and fully undocumented parameters, an agent still lacks guidance on lyric_mode and on confirming this call has no side effects.

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 0%, so the schema itself explains neither the required 'lyrics' string nor the 'lyric_mode' option (which has a default of 'auto' but unknown accepted values). The description explains output notation but adds nothing about what these parameters mean or how lyric_mode changes behavior.

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 description states a concrete verb and resource: it shows how each lyric line will be split into notes, and frames the operation as happening 'before making a song'. This clearly separates it from create_song, but it never names or contrasts with the closer sibling lyrics_to_ust, so sibling differentiation is left implicit.

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?

The phrase 'before making a song' implies the intended workflow slot (a preview step preceding creation), which is useful context, but there is no explicit when-to-use/when-not guidance and no routing to alternatives like lyrics_to_ust or render_backing. Usage is implied rather than stated.

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

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

No annotations are provided, so the description carries the full behavioral burden. It discloses the output formats and one default, but says nothing about where files are written, whether existing files are overwritten, naming behavior, or anything about a process that writes two files to disk.

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?

Two short sentences, front-loaded with the action and output, then the one default worth calling out. No filler and every clause carries information.

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 an 11-parameter, side-effect-producing tool with no annotations and no output schema, the description covers a small slice. It never explains the resulting files' location or how the many musical options shape the render, leaving the agent under-informed 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?

Schema description coverage is 0% across 11 parameters. The description clarifies only one of them — that 'bars' defaults to one pass through the progression (a meaning the null default does not convey). The remaining ten parameters (style, tempo, instrument, soundfont, drums, bass, output_dir, etc.) receive no elaboration anywhere.

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 (render) and resource (backing track from a chord progression) plus the output artifacts (.mid and .wav). The word 'only' weakly signals contrast with a fuller-song render, but no sibling is named, so differentiation from create_song is left to inference.

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?

There is no explicit when-to-use guidance and no alternatives are named. The adverb 'only' implies a contrast with other render paths, but the agent must guess which sibling to prefer and under what conditions.

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