ssh_config_lookup

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real information beyond them: the data source (~/.ssh/config) and the fact that it reports the *effective* merged configuration, which tells the agent it is a local, non-mutating resolution rather than a live connection test.

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?

Three short sentences, front-loaded with the action and the returned fields. The trailing 'and all other options from ~/.ssh/config' is slightly redundant after the enumeration, but nothing is bloat.

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?

A single-parameter, read-only, no-output-schema tool; the description plus annotations plus fully documented schema cover what an agent needs to call it correctly. Only the alias-vs-hostname resolution semantics are unstated.

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% for the single required `host` parameter, so baseline is 3. The description does not clarify whether `host` must be a literal Host alias from config or can be an arbitrary hostname/IP subject to wildcard matching — the one semantic point that would add value here.

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 and resource ('Resolve the effective SSH configuration for a host') and enumerates the returned fields (hostname, user, port, identity files, proxy settings), which separates it from the exec/file-oriented siblings. It does not, however, explicitly distinguish itself from the closest conceptual neighbor, ssh_diagnose.

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?

'Use this to understand how SSH will connect to a host' gives an implied context but largely restates the purpose sentence. There is no when-not guidance and no mention of ssh_diagnose or ssh_test as alternatives for connection problems.

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