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

readOnlyHint=true already declares this as a non-mutating read, so the safety profile is covered. The description adds that all fields are returned and gives the underlying endpoint, but says nothing about error behavior (missing id), permissions, or pagination/expansion options — modest added value over annotations.

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 short sentences with the primary behavior front-loaded; no filler. The API endpoint clause is marginally redundant for an agent but cheap and factual.

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 trivial single-id read with no output schema, the description gives the required parameter meaning, confirms all fields are returned, and pairs with readOnlyHint to convey safety. Nothing an agent needs 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?

With a single parameter at 100% schema description coverage, the baseline is 3; the schema already documents hour_id and its numeric pattern. The description only restates that lookup is by id and adds no format or constraint 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?

States a specific verb and resource ("Get one hour") and scopes it to a single record by id, which implicitly contrasts with the list_hours sibling. It stops short of naming the alternative tool, so differentiation relies on inference.

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?

"by id" implies the precondition that the caller already has an hour id and wants one record rather than a listing, but there is no explicit when-to-use statement, no mention of galaxydigital_list_hours as the alternative, and no guidance on what happens if the id is unknown.

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