editor_get_open_tabs

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

Annotations already establish readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds genuinely new context by disclosing what comes back (all open tabs, active tab marker, split-screen structure), which matters because there is no output schema. It could still mention ordering or multiplicity limitations.

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?

Two short sentences, no filler, and the primary result (open tabs) is front-loaded ahead of the secondary result (split screen structure). Every clause earns its place.

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 simple read-only query tool with complete annotations and a well-documented parameter, the description covers everything needed to invoke it: what it returns and how the active tab is identified. Only richer return detail (ordering, per-tab fields) would add value.

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%; the single instance_id parameter is fully documented in the schema, including the multi-instance and auto-selection behavior. The description adds nothing about the parameter, so the baseline 3 applies.

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 and resource ('Get all currently open tabs in the editor') and adds scope detail ('active tab marked', 'split screen structure'). It is clearly distinguishable from editor_get_current_document by implication (all tabs vs. one), but it never names or contrasts a sibling explicitly.

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 explicit when-to-use, when-not-to-use, or alternative is stated. Usage is only implied: an agent can infer this is how you discover which tab is active versus calling editor_get_current_document. That is implied guidance, not stated guidance.

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