env_keys

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

With no annotations, the description carries the behavioral burden. It discloses key mechanics: each list entry is one keystroke, chords land as chords, the ctrl run is literal, and the environment must be running. It does not discuss invalid-key handling or focus requirements, but the core side-effect profile is transparent.

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 longer than minimal, but every sentence is functional: purpose, usage boundaries, prerequisite, and valid keys all earn their place. It is slightly dense due to the key-name enumeration, but nothing is wasted.

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 two-parameter tool with an output schema, the description is essentially complete: it provides prerequisites, valid inputs, behavioral semantics, and sibling-tool routing. Minor gaps such as error behavior are not critical for correct invocation.

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 already 100%, but the description adds significant value beyond the schema by enumerating valid key names and clarifying chord semantics. The 'name' parameter is not expanded, but that is already adequately described in the schema.

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: 'Press keys and chords in the environment.' It immediately scopes itself against env_type ('that env_type cannot express') and distinguishes itself from mouse tools, so an agent can tell what it does and what it is not.

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?

Explicitly says when to use this tool versus env_type, names env_click and env_scroll as the alternatives for mouse actions, and states the prerequisite that the environment must be running. This gives clear decision criteria for tool selection.

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