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

Annotations already declare readOnlyHint=true, so the read-only safety profile is established. The description adds the HTTP GET method and endpoint path, which is mildly useful context, but it does not disclose potential error behavior, return shape, or any rate-limit concerns. With annotations covering the safety dimension, this is adequate but not rich.

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?

One concise sentence states the action, resource, and API endpoint. There is no filler or redundant repetition; every phrase earns its place.

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-parameter read-only lookup, the description is largely complete. It does not describe the return payload, but the absence of an output schema and the simplicity of a get-by-id operation make this a minor gap rather than a critical omission.

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 description coverage is 100% and 'Orb plan id.' already documents the single parameter. The description reinforces that plan_id is used in the URL path via GET /plans/{plan_id}, adding slight extra meaning, but this does not significantly exceed what the schema already conveys.

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 states a specific verb ('Fetch'), a specific resource ('a single plan by id'), and the exact API endpoint. This clearly distinguishes it from sibling tools like orb_list_plans, which return multiple plans.

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 implies the tool should be used when the agent has a specific plan_id and needs a single plan. It does not explicitly contrast with orb_list_plans or state when not to use it, leaving the routing decision to inference from sibling names.

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