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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds only the upstream API reference ('groups/getInfo') and the hint that members can be pulled in via fields=["people"]; it says nothing about error behavior when an id is invalid or absent.

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?

A single front-loaded sentence that pairs the core action with the optional members flag, followed by a short API reference. Efficient, though the 'Elvanto: groups/getInfo' trailer is of marginal value to an invoking agent.

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 simple, read-only, two-parameter lookup with full schema coverage and a readOnlyHint annotation, the description covers what is needed to invoke it. It stops short of describing the returned group shape, which matters slightly since no output schema exists.

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 both parameters (id and fields) are already documented with an enum-style field list in the schema. The description adds a usage example for fields=["people"] but no syntax or semantics beyond what the schema provides, making 3 the correct baseline.

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 with scope: 'Fetch one group by id', which implicitly separates it from elvanto_list_groups. It is clear, but never explicitly distinguishes itself from the sibling list/search tools the way a 5 would.

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?

There is no explicit when-to-use or when-not-to-use guidance. The agent is left to infer that this tool is for retrieving a single known group id rather than browsing, and the more obvious alternative (elvanto_list_groups) is never named.

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