update_media_grabbers_devices_by_device_id_prefs

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

Annotations already carry the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false). The description adds the HTTP PUT verb, which aligns with and implicitly confirms idempotency, but adds no further context about effects, auth requirements, or whether existing preferences are overwritten or merged. No contradiction with annotations; minimal added value.

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 text is short and the one-line purpose is front-loaded, but the Args block largely duplicates parameter information already present in the schema, and because it adds confusing semantics rather than clarity, its lines do not fully earn their 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?

For a write operation with an output schema and 0% schema description coverage, the description is under-specified. It never explains what kinds of preferences exist, whether name/value are a pair, what happens to existing preferences, or whether changes take effect immediately. An agent has enough to guess the call shape but not to use it safely or correctly.

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 description bears the full burden. It attempts to explain args but poorly: 'name: The preference names and values' is garbled and plural, while the schema shows a single nullable string. The relationship between name and value is not clarified (e.g., do they form a key-value pair? can multiple preferences be set in one call?). An agent cannot confidently construct a correct payload from this.

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 states a specific verb and resource: 'Set device preferences.' The HTTP path clarifies the target (media grabbers devices). However, it doesn't differentiate from sibling _prefs tools like update_livetv_dvrs_by_dvr_id_prefs or update_library_sections_by_section_id_prefs, relying on the tool name to carry the distinguishing resource context.

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, no exclusions, and no reference to alternatives such as update_media_grabbers_devices_by_device_id (updating the device itself) or update_media_grabbers_devices_by_device_id_channelmap. The description provides the endpoint and args but gives an agent no basis for deciding between this and the several sibling update tools.

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