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

The description adds real context beyond readOnlyHint=true: it discloses the return payload shape (channels, timeout, status) and, importantly, the authentication precondition that the client must be authenticated for this specific tool. That prerequisite detail is not captured by annotations and is operationally significant.

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?

Purpose is front-loaded in one sentence, followed by a clearly separated ACCESS note. The parenthetical Claude Code hint is slightly verbose but serves a practical recovery path, and no sentence is wasted.

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 single-parameter read tool with no output schema, the description covers purpose, return contents, and the authentication prerequisite. An agent has what it needs to invoke it correctly, with only the sibling-routing detail left implicit.

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% with a single parameter clearly described as the 'HITL config ID' in the schema. The description's 'by ID' adds nothing beyond what the schema already states, so the baseline of 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?

States a specific verb and resource ('Get a HITL config by ID') and even names the returned fields (channels, timeout, status). It distinguishes itself from create_hitl/update_hitl/delete_hitl via the 'by ID' read framing, though it doesn't explicitly contrast with list_hitls.

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 ACCESS block gives strong prerequisite guidance (needs a Proof account, authenticate first, start_login won't unlock this tool), which is genuinely useful. However, it offers no guidance on when to prefer this over list_hitls for retrieval, so usage is only implied by the 'by ID' phrasing.

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