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

readOnlyHint=true already declares the safety profile, so the bar is lower, and the description still adds real value: matches are exact-only, non-unique fields like name can return multiple records, and results land in the `customers` object. It does not mention pagination or result caps, which is a minor remaining gap.

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?

One tight sentence carrying the matching rules, multiplicity caveat, and result location, plus the endpoint reference. Nothing is wasted and the key constraint (exact matches) is 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 search tool with full schema coverage and no output schema, the description covers matching semantics, multiplicity, and where results appear. Missing only the relationship to checkfront_get_customer, which is what an agent would most want to disambiguate.

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 each parameter is already documented with the same 'exact' semantics. The description reinforces exact-match behavior and adds the non-uniqueness caveat, but provides no new syntax, format, or field-combination guidance beyond the schema.

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 ('look up customers') plus the fields used for matching (email, full name, phone), so the agent knows exactly what this does. It does not differentiate itself from the closest sibling checkfront_get_customer (single-record fetch by id), leaving that routing decision to inference.

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 by the constraint that all matches are exact, which tells the agent this is not a fuzzy search. However, there is no explicit guidance on when to use this versus checkfront_get_customer, nor any statement that at least one search field should be supplied.

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