ddflow_companions

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

With no annotations provided, the description carries the full behavioral burden and meets it well. It explicitly states the tool is read-only, that it detects and advises rather than installs, and it explains what exit 2 means, which is critical for interpreting invocation results.

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 front-loaded with the tool's purpose, and each subsequent sentence earns its place by explaining gate semantics, the no-companion implication, exit-code meaning, and read-only behavior. There is no filler, repetition, or vague padding.

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 tool with no required parameters and no output schema, the description provides strong context: what it reports, the domain rules around gates, and a key error condition. It falls just short of perfect because it does not sketch the expected result structure or what a healthy versus unhealthy companion setup looks like beyond exit 2.

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?

The schema already fully documents the single parameter no_probe with 'Skip the detection probes (faster, less certain)', so the description does not need to add much. The description's detection language aligns with the parameter, but adds no new semantic detail beyond the schema.

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 the resource (companion MCP servers) and the three dimensions it reports on: which serve the project's gates, which are installed on the machine, and which are wired into an agent's config. It also distinguishes itself from the mutating sibling ddflow_companions_add by framing this as a read-only inventory.

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 gives clear context for when the tool is relevant: checking companion coverage for gates, understanding the consequences of having no companions, and diagnosing the exit-2 condition. It does not explicitly name alternatives or exclusions, but the read-only inventory purpose is distinct enough that no sibling tool covers the same role.

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