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

readOnlyHint=true already tells the agent this is a safe, non-mutating read. The description adds only the REST endpoint mapping, which offers little behavioral context beyond that — no note on 404 behavior for unknown ids, idempotency, or what the returned resource contains. With annotations carrying the safety profile, this is thin added value.

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, front-loaded with the access pattern and capped by the endpoint reference — no padding or repetition. The endpoint sentence is close to boilerplate across this tool family, keeping it just short of a 5.

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 one-parameter read whose safety profile is covered by annotations, the description is sufficient to invoke the tool correctly. The only real gap is that, with no output schema, it never indicates what a fetched floating IP record contains or how failures (unknown id) surface.

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?

There is a single integer 'id' parameter with 100% schema description coverage ('The resource's numeric id.'), so the schema fully documents it. The description adds no format, range, or sourcing guidance for the id (e.g., where to obtain it), so the 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?

The description gives a specific verb and retrieval mode ('Fetch a single resource by id') and the endpoint path GET /floating_ips/{id} identifies the resource type and distinguishes it from the sibling list_floating_ips. It loses a point because the prose itself calls it a generic 'single resource' rather than naming floating IPs, relying on the endpoint string to carry that meaning.

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 'single resource by id' phrasing implies usage (fetch one known record rather than enumerate), which separates it implicitly from list_floating_ips. However, there is no explicit statement of when to prefer this over the list variant, nor any prerequisite/error guidance for a missing or invalid id.

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