update_metadata

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

With no annotations provided, the description must fully disclose behavioral traits. It only mentions the mutative ops flag, but does not specify whether updates are partial or full replacements, whether changes are irreversible, or any other side effects. This leaves significant behavioral uncertainty for an agent.

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 description is a single sentence that front-loads the purpose ('Update metadata fields for a media item') and immediately follows with a prerequisite. There is no wasted wording, and the structure is highly efficient.

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 the high parameter count (14), no output schema, and no annotations, the description carries a heavy burden. It lacks essential context such as update semantics, return values, applicable media types, or any caveats beyond the mutative ops flag, making it incomplete for an agent to safely invoke.

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 input schema provides 100% coverage with descriptions for all 14 parameters, so the baseline is 3. The description adds no additional parameter-specific meaning beyond what the schema already offers.

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 clearly states the tool's function: 'Update metadata fields for a media item,' using a specific verb and resource. It is unambiguous, but it does not explicitly distinguish itself from the sibling tool 'update_metadata_from_json', so it falls short of a 5.

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 only usage-related information is the prerequisite 'requires PLEX_ENABLE_MUTATIVE_OPS=true'. It does not provide any guidance on when to use this tool versus alternatives like 'update_metadata_from_json' or 'get_editable_fields', nor does it mention exclusions or scenarios where this tool is preferred.

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