Cancel previewed Jev navigation

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

Annotation contradiction: readOnlyHint=true asserts the tool does not modify its environment, yet the description says it consumes (invalidates) a single-use token and closes an isolated browser — both are side effects on state. The description directly contradicts the annotation's safety claim, which is exactly the case the rubric flags.

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?

One 14-word sentence that front-loads the primary action (consume token) followed by the secondary effect (close browser). Every word earns its place, and the most decision-relevant detail — 'without navigating' — is positioned early.

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 one-parameter tool with annotations and no output schema, the core behavior is described adequately. However, edge cases are unaddressed (behavior on an already-consumed or invalid token, what the tool returns), and the readOnlyHint contradiction muddies what the agent should expect. Adequate with clear gaps.

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%, with the token parameter documented as a single-use token returned by jev_guard_preview plus a format pattern. The description's 'pending preview token' aligns with this and adds only marginal meaning (the pending state). Baseline 3 applies because the schema carries the semantic weight.

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 action ('consume a pending preview token', 'close its isolated browser') with a clear resource. The phrase 'without navigating' explicitly distinguishes it from the execute sibling, and the token provenance from jev_guard_preview is established in the schema. The cancel/preview/execute trio is fully differentiated.

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?

The description provides clear operational context: this is the path for not navigating, consuming the pending token and closing the browser. It implies it is the alternative to jev_guard_execute for aborting a preview, though it never explicitly names siblings or states when-not conditions. Clear context, but no explicit exclusions.

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