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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds real value by disclosing pagination semantics ('one Tookan page per call', page defaults to 1) and enumerating the returned fields, which the agent needs to plan iteration. It stops short of stating page size, how to detect the last page, or rate limits.

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 sentences, front-loaded with the core action and result fields, followed by search and pagination behavior plus the endpoint. No filler and nothing important buried.

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?

With no output schema, listing the returned fields in the description is the right compensation, and pagination behavior is explained. The only remaining gap is how an agent knows it has reached the last page, which matters for a paginated list tool but is a minor omission.

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 all three parameters are already documented in the schema, including the page default and the fixed page size. The description restates the same facts (name/phone as optional search, page default 1) without adding syntax or format guidance, so the baseline 3 applies.

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 and resource (list customers), names the returned fields, describes the optional name/phone search, and identifies the underlying endpoint. It does not, however, differentiate itself from the sibling tookan_find_customer_by_phone, which overlaps with the phone-search behavior described here, so an agent still has to guess which one to pick for a lookup.

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 implied: 'optionally searched by name or phone' suggests when to pass filters, and the pagination note suggests when to page. There is no explicit when-to-use or when-not-to-use statement, and no routing guidance versus tookan_get_customer or tookan_find_customer_by_phone, which is the most likely point of confusion.

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