Read any Fortnox endpoint

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is established. The sentence "nothing that sends, prints or changes data is reachable" largely restates readOnlyHint rather than adding new traits such as pagination limits, rate limits, or how invalid paths are handled. With annotations doing the heavy lifting, a 3 is appropriate.

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 sentences, no filler. The operational constraint (must match a list_endpoints template) is front-loaded before the read-only guarantee, which is the right ordering for an agent deciding whether it can call this.

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 an open-world GET passthrough with no output schema, the definition covers the calling contract: where paths come from, their shape, and that reads are safe. It omits pagination/query semantics and invalid-path error behavior, which are minor but non-trivial for a generic proxy.

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 the baseline is 3, but the description adds meaningful context: the path is a concrete instantiation of a discovered template with {placeholders} filled in, and it shows two worked examples. That clarifies how to derive the required value beyond the schema's terse "Concrete path" note.

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 (GET) and resource (a Fortnox API path) and ties it to a discovery source (templates from list_endpoints) with concrete examples. An agent can distinguish this generic passthrough from the domain-specific siblings like list_customers or get_invoice without opening any schema.

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 description makes the precondition explicit: the path must match a template obtained from list_endpoints, with placeholders substituted. It does not state when to prefer this generic tool over the purpose-built siblings (e.g. get_customer), which is the one remaining routing gap.

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