set_value

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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered structurally. The description adds nothing beyond this—it doesn't explain what happens to the prior value, whether confirmation is required, or any failure modes.

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 no wasted words, but it is under-specified rather than genuinely concise for a destructive mutation tool. It is minimal without being information-dense.

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 destructive, non-idempotent mutation with a confirmation_token in the schema, the description omits the confirmation/approval workflow and any context about which elements are 'settable'. No output schema exists, so the description could have carried more of this burden.

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 four parameters (including the confirmation_token) are already documented in the schema. The description adds no parameter meaning, which is acceptable given the baseline-3 rule for high coverage.

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 states a specific verb+resource ('Set the value of a settable accessibility element'), so an agent knows it mutates an existing element's value. However, it offers no differentiation from siblings like type_into, type_text, or click_text, which could also write values into UI elements.

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 guidance on when to use this versus type_into or type_text, no prerequisites, and no mention that a high-risk action may require a confirmation token. The agent must infer usage entirely from the terse statement.

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