align_lyricsPROJECT-SCOPED: this call acts only on the explicit project_id and returns the project identity with its result. READ: the user's lyrics text aligned to the singer's timing on their track (after separate_music).
| Name | Required | Description | Default |
|---|---|---|---|
| lyrics | Yes | ||
| music_id | No | ||
| project_id | Yes | Required immutable scope for this call. Copy the id from list_projects/open_project/project_state; the active-project pointer is never used to guess. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, non-destructive, closed-world). The description adds real behavioral context beyond them: the call is strictly project-scoped to the explicit project_id, it returns the project identity alongside the result, and it presupposes separate_music has run. It does not explain why idempotentHint is false, which is the one noteworthy trait left undisclosed.
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, both front-loaded with the highest-value information (scope first, then what is read and its prerequisite). The uppercase labels are terse and functional rather than wasteful, though slightly telegraphic.
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 the description must convey returns, and it does say the result comes back with the project identity. However, it never states what the aligned output actually contains or whether alignment is persisted to the project, and it leaves the required lyrics parameter's expected shape unexplained.
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 only 33%: project_id is well documented in the schema, but the required 'lyrics' parameter and optional 'music_id' have no type, format, or usage detail in either place. The description says only 'the user's lyrics text', which leaves the critical question of expected lyric format (plain lines, timestamps, syllable breaks) unanswered.
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 a specific verb (align) and resource (the user's lyrics text) and states the alignment target (the singer's timing on their track). The parenthetical 'after separate_music' links it to a specific sibling and workflow stage, though it doesn't contrast with near-neighbours like get_syllables, get_words, or beat_align_cuts.
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 through the 'READ' label and the 'after separate_music' ordering prerequisite, which is genuinely useful sequencing information. There is no explicit statement of when to prefer this over alternatives such as get_syllables or get_words, nor any when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.