move_firefox_tab_to_group

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

With no annotations, the description must carry the full behavioral burden. It does disclose useful behaviors: 'verify the result' indicates a post-condition check, and 'Ambiguous matches fail safely' signals non-destructive handling of ambiguous selectors. However, it does not mention side effects like unpinning, permission requirements, or what happens on failure (e.g., error messages, no-op). For a mutation tool, this is modest transparency and justifies a 3 rather than a higher score.

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?

The description is a single, front-loaded sentence that states the action, target, and key constraints ('exactly identified', 'existing', 'same window', 'verify', 'fail safely') with zero filler. Every phrase contributes to selection and safe invocation, making it an exemplar of conciseness.

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?

The tool has no output schema and no annotations, so the description should cover outcomes and errors more. It mentions 'verify the result' but does not describe what the verification returns or how failures are reported. It also does not clarify prerequisites (e.g., group must exist, tab must not be pinned unless allowUnpin). While the schema covers parameters, the description leaves some operational gaps for an agent planning invocation.

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%; each parameter is already well-documented (e.g., selector forms, allowUnpin for pinned tabs, groupTitle case-sensitivity). The description adds no parameter-level meaning beyond the schema, so the baseline 3 applies. It does not compensate or add extra nuance, but no compensation is needed.

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?

Description uses a specific verb+resource: 'Move one exactly identified Firefox tab into an existing, exactly named group in the same window.' It clearly distinguishes from siblings by emphasizing 'one', 'existing group', and 'same window', contrasting with move_firefox_tabs_to_group (multiple), move_firefox_tab_to_window (window target), and move_firefox_tab (likely generic move). The phrase 'exactly identified' and 'exactly named' further narrows scope.

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 implies when to use this tool: when moving a single, uniquely identified tab to an existing group in the same window. It does not explicitly name alternatives (e.g., 'use move_firefox_tabs_to_group for multiple tabs' or 'use move_firefox_tab_to_window for different windows') and lacks explicit exclusions. The context is clear but no explicit when-not guidance is provided, so this falls short of a 4 or 5.

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