Current State

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

With no annotations, the description carries the burden and does disclose two meaningful traits: it is cheap (cost profile) and it dedups identical state (caching behavior that affects repeated calls). It omits error/precondition behavior and never explains what force_refresh does in relation to that dedup, which is the main behavioral gap.

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?

Four tightly packed lines: purpose and cost first, then placement in workflow, then dedup behavior, then a concrete input/output example. No sentence is filler and the most decision-relevant facts are front-loaded.

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?

An output schema exists, so return values need not be explained, and the description still sketches the payload. Combined with the cost and dedup notes it is nearly complete, but the unexplained force_refresh parameter leaves a real gap for a 2-parameter tool.

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 0%, so the description must compensate. The example current_state('t0') does illustrate the tab_id format, but force_refresh is never mentioned in the description despite being directly relevant to the 'dedups identical state' claim — an agent cannot infer what it does or when to set it.

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 exactly what the tool returns (URL, title, h1/h2, forms, interactive_count) and frames it as cheap orientation, which is a specific and concrete resource definition. It also explicitly differentiates from the sibling aria_snapshot by calling itself 'lighter', so an agent can choose between them without opening either 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?

'Good first move after navigate' gives explicit positioning in the workflow, and 'Lighter than aria_snapshot' implicitly tells the agent when to escalate to the heavier sibling. There is no explicit negative case (e.g., when not to use it, or that it requires an open tab), so it stops short of a full 5.

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