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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false. Beyond that, the description discloses ordering (newest first), status lifecycle (pending until approved), conditional expiry date, the two email/signed markers, and the API-key access requirement, which is substantial behavioral context.

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 first sentence front-loads the returned fields, but the third sentence redundantly repeats the status, expiry date, and email/signed markers. The fragmentary opening also wastes some space, though the overall length is not excessive.

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?

No output schema exists, so the description must describe returned content. It covers fields, ordering, status semantics, expiry behavior, and the two list markers, plus the auth requirement, which is complete enough for an agent to call and interpret the 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 description coverage is 100%, so the schema already documents limit, cursor, and search completely. The description adds no additional meaning for those parameters; its estimate_id mention is for other tools, not an input here.

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: "Lists the estimates in your Joist account, newest first." It also names the key handoff to convert_estimate_to_invoice/get_document via estimate_id, helping distinguish this list tool from single-document siblings.

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?

It gives concrete downstream usage ("Pass estimate_id to convert_estimate_to_invoice or get_document") and an auth prerequisite ("Needs the user's Cotlet API key with access to this app"). However, it never states when to prefer this over list_invoices or when not to use it, so it lacks explicit alternatives/exclusions.

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