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

With no annotations, the description carries the full burden and does disclose real behavior: it requires a JWT and is scope-filtered so non-admins see only their member companies. However, it omits return format, ordering, and whether the result is paginated, which matters for a list tool.

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 fragments with the resource and the scoping constraint front-loaded; nothing is wasted. The parenthetical '(jwt, scoped)' is telegraphic but readable.

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 parameterless list tool with no output schema, the description covers what an agent needs to know: the auth requirement and the authorization-scoped visibility. Return shape is unspecified but the operation is simple enough that this 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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to add or clarify. The '(jwt, scoped)' note is context rather than parameter documentation, which is acceptable given an empty schema.

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 ('List') and resource ('companies'), which cleanly separates it from the singular sibling get_company. It does not explicitly name or contrast with alternatives, but the verb+resource is unambiguous.

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 by the name and the scoping note; there is no explicit when-to-use or when-to-prefer-get_company guidance. The 'Non-admins see only their member companies' clause hints at the intended audience without routing the agent between options.

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