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

readOnlyHint=true already establishes this as a safe read operation, so the description is not carrying the safety burden. It adds the useful note that detail is opt-in via fields, but says nothing about auth requirements, error behavior for a missing id, or response size — modest added value over the 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?

Front-loaded with the core action and scoped in two compact sentences with no filler. The trailing "Elvanto: services/getInfo." API pointer is marginally useful metadata, but the field enumeration in sentence one and the schema's enum list duplicate each other somewhat.

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?

With no output schema, the description sensibly enumerates the returnable content so an agent knows what it can retrieve, which is the key missing piece. For a read-only fetch by id with fully documented params, this is close to complete; error/empty-result behavior is the only untouched area.

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 description coverage is 100%, so both `id` and the `fields` enum are already fully documented in the schema. The description's parenthetical glosses ("plans (the order of service)", roster semantics) largely restate schema text rather than adding new meaning. Baseline 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 ("Fetch one service by id") and enumerates the payload it returns (times, plan, roster, songs, files, notes). The singular "one service" clearly contrasts with elvanto_list_services, but the sibling is not named outright, so the differentiation is implied rather than explicit.

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?

"with optional detail" signals that the `fields` argument expands the response, which is useful implied guidance for when to pass it. However, there is no explicit when-to-use, no when-not-to-use, and no alternative (e.g. elvanto_list_services for discovery) is named, leaving routing to inference.

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