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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description goes well beyond them: it discloses old-slug rename following, the error-with-reason for delisted companies, suggestions for unknown names, and the 60-car fleet cap with fleet_total as the true count. These are exactly the edge behaviors an agent cannot infer from structured fields.

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?

Front-loads the scope, then the usage trigger, then edge cases and the fleet cap. The opening field enumeration is somewhat long, but every clause carries information an agent would otherwise have to discover by trial; no filler sentences.

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?

An output schema exists so return shapes needn't be explained, yet the description still tells the agent what categories come back and how to handle failure modes (delisted, unknown), which is more than sufficient for a one-parameter lookup tool.

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's schema description already covers 'slug from url, old slug, or exact name'. The description largely restates this, though the 'follows renames' nuance and the name-fallback behavior add slight value over the schema. Baseline 3 is appropriate.

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 (get) and resource (one company) and enumerates the payload: contact details, rental terms, fleet with daily rates, recent price changes. It is clearly distinguishable from siblings like search_companies and top_companies because it is scoped to a single identified company.

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?

Gives an explicit trigger ('when someone names a company or picks one from search_vehicles results') and even the calling pattern (pass company.slug). It lacks an explicit negative case (e.g., use search_companies when you don't have a name/slug), but the context is clear.

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