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

Annotations declare readOnlyHint and idempotentHint, but the description adds materially more: 'value-blind', reads only whether each env var is set, 'no values, no network, no writes', via a single read-only probe. These are real behavioral guarantees beyond the annotation set, so the agent knows the blast radius and data exposure precisely.

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?

Dense but front-loaded: purpose, then safety profile, then parameter semantics, then return shape, then usage. Every clause carries information, though the parameter and return sentences are packed tightly enough that it reads more like a spec block than prose.

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?

Even though an output schema exists, the description still sketches the return shape (`present`/`missing` arrays plus per-credential `var`, `purpose`, `url`, `method`, `command`), which makes the tool self-sufficient for an agent deciding whether to call it. Nothing needed to invoke it 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%, so baseline is 3, but the description earns an extra point by explaining the consequence of `target`: it selects the machine (local or SSH) and drives the returned `template` path and the env file the presence check reads. Minor gap: it references a `home` field that is not present in the schema's target object, which could momentarily confuse an agent about the shape of the parameter.

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?

Opens with a specific verb+resource (list the credentials the profile references) and immediately distinguishes three output categories: already-provided, referenced, and how to acquire missing ones. An agent can tell exactly what this returns without opening the schema, and it reads distinctly from siblings like run_auth_flow or plan_clone.

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 sequencing ('Use it after plan_clone to see what would degrade') and names the correct follow-up action for a single credential ('act on one credential with run_auth_flow'). This is textbook when-to-use plus named alternative routing.

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