browser_group_tabs

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: the default group title is the agent's name, the full set of accepted color strings, and the failure signal (updated=false plus a warning when Chrome did not apply the title, color, or collapsed state). It stops short of saying what happens to tabs outside tab_ids or whether a new group is created each call.

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, with the core action front-loaded before the color list and the response caveat. The inline 'Response:' fragment on its own line is slightly awkward formatting but carries no wasted words.

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, the description does supply the key return semantics (updated=false + warning), which is valuable. For a mutating tool it is still thin: nothing on group-reuse behavior, multi-window constraints, behavior with invalid or already-grouped tab_ids, or what updated=true guarantees.

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 coverage is 0%, so the description carries the burden. It compensates well for two parameters by enumerating the nine valid color strings (the schema has no enum) and explaining the title default, and it references the 'collapsed state'. However, tab_ids (the only required parameter) and the meaning of 'collapsed' are never explained, leaving the most important input undocumented.

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 names a specific verb and resource: it puts tabs of the current session into a named, colored tab group, and it clarifies the default title source (the agent's name). No sibling tool performs grouping, so there is no real ambiguity, but the description never explicitly routes the agent (e.g. to browser_list_tabs for the ids) or states whether an existing group is reused.

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?

Usage is implied rather than stated: 'tabs of this session' hints at the scope, but there is no explicit when-to-use/when-not-to-use guidance, no prerequisite about obtaining tab_ids, and no note on what happens if the tabs span multiple windows. An agent can infer the context but must guess the boundaries.

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