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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds the useful caveat that docs may not exist ('if present'), but says nothing about what an empty result looks like or how missing-device errors surface.

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 tight sentences: the action comes first, the parameter derivation second. No filler, and the most load-bearing detail (the slug format) is not buried.

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 an output schema present, return values need no explanation, and annotations plus the two documented parameters leave little ambiguity. Only the behavior on missing documentation is left implicit.

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 coverage is 100%, so the baseline is 3, and the description genuinely adds meaning beyond the schema by defining the slug as the device's OSC prefix minus the leading slash (e.g. 'ableton' for /ableton). The optional user_id is left entirely to the schema text.

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 resource (fetch markdown companion documentation for one device) plus a scope qualifier ('if present'). An agent can distinguish it from list_devices or submit_driver, though it never names a sibling it might be confused with.

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?

Implies the usage context through 'if present' and explains how to derive the slug from an OSC prefix, but gives no explicit guidance on when to prefer this over siblings such as list_devices for discovering a device, nor what to do when documentation is absent.

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