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

Beyond the read-only/idempotent annotations, the description adds useful behavioral context: the output is Markdown with a defined structure, facts are dated and labelled observed/first-party/third-party, and the Verify-first checks must be run before relying on the content. It does not cover failure behavior for a missing slug, but the return-content expectations are unusually well disclosed.

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?

The description is compact and front-loaded: the first clause states the return format, the content list is dense but purposeful, and the final instruction about Verify-first checks is placed where it will be seen. There is no unnecessary wording.

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?

With one fully described parameter, read-only annotations, and no output schema, the description covers the main need: what the route document contains and how to interpret its provenance labels. Missing-slug behavior is not addressed, but that is a minor gap relative to the tool's simplicity.

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 slug parameter already includes an example and its source tool, find_routes. The description adds no additional parameter meaning, which is appropriate because the schema is doing the full job.

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 makes clear that this returns the full route document as Markdown and lists exactly what the document contains: TL;DR, verify-first checks, per-site facts, dead ends, prices, checklist, and human-review items. It does not explicitly contrast itself with sibling tools like get_execution or get_quote, but the route-document scope is still clear.

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: the schema says the slug comes from find_routes, which suggests calling find_routes first, and the description says to run the Verify-first checks before relying on the route. It does not state when to use this rather than get_execution, get_quote, or other siblings.

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