code_show_source_control

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: it waits for content to appear, and a press on an already-selected view collapses the sidebar and 'reports honestly as a failure.' That failure semantics is exactly the kind of edge case an agent needs, though return values/success payload are unaddressed.

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 sentences, front-loaded with the primary action and followed by the edge-case caveat, with no filler. The second sentence is slightly informal ('reports honestly as a failure') but earns its place by warning of a real trap.

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 zero-parameter UI automation tool with no output schema, the description covers what it does, its timing behavior, and its main failure mode. Nothing an agent needs to call it correctly is missing, though it offers no hint of the return shape or how to recover from the collapse failure.

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?

Parameter count is 0 and the schema has no properties, so there is nothing for the description to compensate for. Baseline of 4 applies for a parameter-free tool.

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?

States a specific verb (Select) and resource (the Source Control view in the VS Code activity bar), and the sibling set (code_show_explorer, code_show_search) makes the differentiated target unambiguous. An agent can tell this apart from the other view-selection tools without opening a schema.

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: invoke this to bring the Source Control view into focus and wait for it to render. It adds a useful condition (already-selected view collapses the sidebar and fails), but it never names the sibling alternatives (explorer/search views) or states when to prefer this tool over them.

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