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 that configuration is included in the response, but says nothing about error behavior (e.g., not-found), permissions, or auth requirements.

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 action and resource, and the API endpoint reference is compact and useful. No filler.

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 single-resource GET with full schema coverage and a readOnly annotation, this is adequate. It lacks return-value detail, but that's forgivable given the endpoint reference; still, no output schema means the agent has only a vague sense of what 'configuration' contains.

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% and the single parameter is fully documented in the schema. The description adds nothing about the id format or source beyond what's already provided, 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?

States a specific verb (Fetch) and resource (a single reactor) with configuration scope. The 'single reactor' phrasing distinguishes it from the sibling basis_theory_list_reactors, but it doesn't name that sibling explicitly, leaving differentiation implied by the singular/plural contrast.

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 word 'single' plus the reactor_id parameter implies this is the detail-lookup counterpart to a list call, but there is no explicit when-to-use or alternative naming. Usage is inferable rather than stated.

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