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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false. The description adds the key non-obvious context that it returns step-by-step instructions and performs no action itself, which is useful beyond the annotations. However, it does not explain the structure of the returned steps, any account or authentication prerequisites, or how the target invoice is determined, leaving gaps.

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 a run-on with multiple embedded clauses, including a parenthetical date-check claim and an API-availability tangent. The core distinction (returns steps, does not perform the action) is not front-loaded and is diluted by API trivia.

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 zero-parameter instruction-returning tool, the description should explain how the returned steps relate to the browser tools and what the agent should do with them. It gestures at this, but the API-availability tangent and missing return-format detail leave it only adequate.

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 has zero parameters, so the baseline is 4. The description correctly implies no inputs are required and focuses on explaining the output and the follow-up action, which is appropriate for a parameterless tool.

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 and resource ('Send invoice in the user's own Invoice Ninja account') and clarifies that the tool itself only returns step-by-step instructions rather than performing the send. That distinction is important, though it is somewhat buried in a long sentence and does not explicitly differentiate it from the invoice_ninja_create_invoice sibling.

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 explains the workflow context: it says the tool 'opens nothing by itself' and that the actual action is done 'with the cotlet_browser_* tools in the user's Invoice Ninja Cloud Browser.' This tells the agent how the tool fits into a sequence, but it does not state when to prefer invoice_ninja_create_invoice or other sibling tools over this one.

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