Find customers

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

Beyond readOnlyHint/openWorldHint, it discloses non-obvious behavior: 100 results per page scanned up to max_pages, and that a match on an email/phone fragment still confirms that detail exists on the account. This is real operational context (cost/latency and match semantics) not derivable from annotations, though it omits anything about rate limits or result ordering.

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?

Four tight sentences, front-loaded with the core search behavior followed by the paging constraint, the default projection, and a subtle caveat. Nothing is wasted and each sentence carries distinct information.

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, the description usefully explains what is and isn't returned (names vs. contact details on request) and how paging bounds the scan. The only omission is the role of max_results, which is undocumented in both the schema and the description.

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?

Adds meaning beyond the 75% schema coverage: the 'query' parameter accepts name/email/phone fragments with the UK 0/+44 spelling rule, and 'include_contact_details' is explained as returning contact fields plus contact-like custom fields (what 'names only by default' means). It leaves 'max_results' unaddressed in both description and schema, a minor gap.

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?

Starts with a specific verb+resource: 'Search customers by part of their name, email, mobile or phone.' It clearly distinguishes a multi-match search from the single-record sibling get_customer, and states the matching scope (name/email/phone fragments, UK number formats).

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?

Gives clear context for when to use it (fragment search, with the UK 0/+44 matching rule) and explains the fallback strategy since 'the API has no search parameter, so this pages through the customer list.' It does not explicitly name get_customer as the direct-lookup alternative, which keeps it short of a 5.

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