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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered and the description does not contradict it. The description adds only label-format tolerance, not behavioral traits such as error behavior on an unknown label or what 'full details' includes.

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 with zero waste; the core purpose leads and the format normalization is parenthetically appended, which is exactly the right priority order.

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 a fully documented schema and no output schema, the description covers what the agent needs to call it. It could have briefly characterized the returned 'full details', but that is a minor gap.

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 genuinely adds meaning beyond the schema by documenting accepted label variants ('3', 'node 3') that the schema's 'NODE_03' example does not mention. It adds nothing about the currency parameter, which the schema already covers.

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+resource combination ('Full details of one node') and scopes it to a single lookup by label, which implicitly contrasts with the sibling list_nodes. It does not explicitly name or distinguish itself from alternatives like estimate_cost or rental_guide, so it stops just short of a 5.

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?

Usage is only implied: 'one node by its label' suggests single-item retrieval versus list_nodes for enumeration, but there is no explicit when-to-use, when-not-to-use, or named alternative. Nothing misleading, but the agent must infer the routing decision.

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