Tag File

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

Annotations provide basic hints (non-destructive, idempotent). The description adds valuable behavioral context: the tool uses ffmpeg, can target by search term, and infers artist/title from filename if not provided. No contradictions with annotations.

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 contain no filler. First sentence states core purpose, second adds two key details (search targeting, inference from filename). Every word earns its place.

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?

Given 7 parameters and no output schema, the description covers main behavior (writing tags, targeting by search, inference). It doesn't mention return value or error handling, but for a write tool, it's reasonably complete. The use of ffmpeg is noted, which implies system dependency.

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 baseline is 3. The description adds the insight that artist and title are optional and can be inferred from the filename, which goes beyond schema descriptions. This is useful for the agent's decision-making.

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?

Description clearly states the action ('Write metadata tags'), the tool ('ffmpeg'), and the resource ('media file'). It also notes the ability to target by search term, which distinguishes it from sibling tools like mpv_info (read-only) and mpv_add (likely adds files to playlist).

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 explicitly states when to use ('Write metadata tags') and implies not for reading (use mpv_info). However, it does not explicitly mention alternatives or when not to use, so it's slightly less than perfect but still clear.

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