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

The description adds real context beyond the annotations: result ordering ('in the order ERPNext lists them'), page size and cursor mechanics ('Pages hold up to 100 customers; pass next_cursor back as cursor'), partial-match search semantics, and an auth requirement ('Needs the user's Cotlet API key with access to this app'). Annotations already cover the safe-read profile, so this is value-add rather than redundancy.

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?

Six sentences, resource-first, and most carry operational information (search semantics, pagination, downstream ID usage, auth). The ordering sentence is mildly expendable filler, but overall it is tight and front-loaded.

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 read-only list tool with no output schema, the description covers the essential agent concerns: what is returned, how to page through it, how to reuse the ID, and what credentials are required. Only the exact returned field set is left unspecified, 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?

With 100% schema coverage the baseline is 3, and the description earns more by clarifying that search is a partial Customer Name match and by specifying the 100-record page ceiling and cursor round-trip, details the schema (which only states the default of 20) does not provide.

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 names a specific verb and resource (list ERPNext customers) and describes the shape of the returned entity (with type, group and territory). It does not need to differentiate from siblings since no other ERPNext tool lists customers, but the 'type, group and territory' phrasing is loose and doesn't map cleanly to the actual filter params.

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 explains how the output is consumed downstream (feed the customer ID into create_sales_invoice, list_sales_invoices, create_payment_entry), which is useful workflow context, but it never states when to call this tool versus alternatives such as searching or a different provider's list_customers. Usage is implied rather than guided.

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