open_file

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

With no annotations, the description carries the full burden. It usefully discloses the platform (Windows) and the side effect on the UI (the note becomes the active tab), which an agent genuinely needs. It omits failure behavior — e.g. what happens if the path does not exist or Obsidian is not running.

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?

A single front-loaded sentence with zero filler opens on the verb and immediately states the effect. It is appropriately sized for a one-parameter tool, though it is too terse to carry any usage routing.

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 simple, one-parameter, no-output-schema tool, the description covers what it does, where it acts (Windows Obsidian UI), and the resulting state. Only error/edge-case behavior is absent, which is a minor gap at this complexity level.

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% and the single 'path' parameter is fully documented in the schema with a concrete relative-path example. The description adds no syntax or format detail beyond that, so the baseline of 3 applies.

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 gives a specific verb and resource ('Abre uma nota na interface do Obsidian no Windows') plus the observable effect ('tornando-a a aba ativa'). That distinguishes it in spirit from read_note or get_active_file, but it never names a sibling explicitly, so the differentiation is left to inference.

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: opening a note in the UI rather than reading its contents suggests this is the user-visible action, contrasting implicitly with read_note. There is no explicit when-to-use statement, no exclusions, and no mention of alternatives such as get_active_file.

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