List tabs

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

No annotations are supplied, so the description carries the full burden. It adds real value by disclosing the return roster, the meaning of the '·front' marker, and the rule that per-tab summaries are only refreshed by summary-bearing actions — but it never states the tool is read-only/non-mutating or whether it requires an active browser session.

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?

Front-loaded with the return-field roster and kept to two terse sentences with no filler. The '·front' clarification is embedded rather than given its own sentence, which is efficient though slightly 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?

With no output schema, this description effectively serves as the return-value documentation by naming every field, including the non-obvious '·front' marker. It is complete enough for a read-only listing call, with the only gap being the absent read-only/statefulness disclosure that annotations would normally cover.

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% and the slot description already explains the 1-30 range, the string-coercion cases, and the port-offset trick, so the schema does the heavy lifting. The description's mention of 'Slot tab list' confirms slot scoping but adds nothing the schema lacks; 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 enumerates exactly what the tool returns (number, ID, title, URL, opener, last action, per-tab summary) and is scoped to a 'slot tab list', so an agent can tell it apart from browser_tab_select, browser_tab_new, and browser_tab_close, which are mutation/selection siblings. It never states the verb 'lists' outright, but the noun phrase 'tab list' plus the field roster makes the read purpose unambiguous.

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?

There is no when-to-use guidance and no routing to alternatives; the agent must infer that this is the discovery step before tab_select or tab_close. The clause about the per-tab summary being 'updated only by actions with summary' is behavioral context, not usage guidance.

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