Fill in a text field

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

Annotations declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, but the description adds what those hints cannot: the field is cleared before typing, keystrokes are translated through the Amiga keymap, and Return is pressed unless no_enter is set. It also discloses the return value (which field was set). Remaining gaps are minor: no statement of what happens when the label matches nothing or when several fields match.

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?

Three tight sentences with no filler, front-loading what the tool does before the prerequisite and the alternative. Slightly dense clause chaining in the first sentence, but every phrase carries actionable information.

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 7-parameter mutation tool with no output schema and 100% schema coverage, the description covers the action sequence, the prerequisite lookup tool, the sibling alternative, the Return-press flag, and the return value. It does not describe failure or ambiguity handling (no match, multiple matches handled via nth), which is the remaining shortfall.

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 100%, so all seven parameters already carry their own documentation. The description reinforces the identifiers (label/id used to locate the field) and the no_enter effect ('press Return unless no_enter is set'), but adds little syntax or semantics beyond the schema. Baseline 3 applies where the schema does the heavy lifting.

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 plus full mechanics: 'Fill a text (string) gadget found by its label: click it, clear it, type the text through the Amiga's keymap, and press Return unless no_enter is set.' It also names the sibling it is not (amiga_key_type for Shell/editor), so an agent can distinguish it without opening any schema.

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?

Gives an explicit prerequisite ("Find the field's label or id with amiga_ui_list first") and an explicit alternative with the condition that selects it ("For typing into a Shell or editor use amiga_key_type"). Both when-to-use and when-to-use-something-else are covered.

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