list_extension_commands

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

Annotations cover the safety profile (readOnlyHint=true), so the lower bar applies. The description still adds real behavioral context beyond annotations: it explains the filtering semantics (commands with dedicated tools are omitted) and the returned line format — command name, parameters with '?' meaning optional, and description. It doesn't discuss pagination, ordering stability, or what happens if a plugin attaches mid-session, so not a 5.

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 core action and scope, then layers in examples, the exclusion rule, and the output format in a tight sequence with no filler. It is a single dense block rather than multiple sentences, so it is slightly harder to scan than an optimally segmented description, but 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 discovery tool with no output schema, the description does the work the schema cannot: it defines what is listed, what is deliberately excluded, the format of each returned line, and the tool to call next. Nothing needed to invoke or interpret the result correctly is missing.

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 100% and the single 'filter' parameter already has a clear description plus examples in the schema. The description adds no further detail about the filter (no matching semantics beyond what the schema says), so the schema carries the parameter load and 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?

Starts with a specific verb+resource: 'List the extension commands (execute methods) available in the current session that have no dedicated tool.' It further pins the scope by naming the upstream source (Appium's listExtensions) and giving concrete examples of what counts (driver 'windows:' commands, plugin bridges like .NET/Java/SAP/PCOMM). This is unmistakably distinct from siblings such as find_element or execute_extension_command.

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?

Explicitly states the exclusion rule: 'Commands already covered by a dedicated tool are left out — use that tool instead,' which routes the agent away from this tool when a dedicated sibling exists. It also gives the follow-up path: 'Run a listed command with execute_extension_command,' naming the exact sibling to use next.

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