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

The annotation only supplies readOnlyHint=true; the description adds the genuinely non-obvious context that the underlying call is a POST yet still read-only, which prevents an agent from mis-classifying it as a mutation. It does not describe pagination behavior or the shape of results, so it stops short of full disclosure.

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?

Three short, front-loaded sentences with no padding; the resource definition and the read-only caveat both appear before the low-value endpoint restatement.

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 simple read-only list tool with a fully documented schema, the description covers purpose and the POST/read-only oddity. It is slightly incomplete in not indicating what a returned identity contains or that results are cursor-paginated, but nothing blocks correct invocation.

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% (limit, cursor, and search are all documented in the schema), so the baseline is 3. The description adds no meaning about filtering or paging beyond what the schema already states.

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 the specific verb (list) and resource (identities), then defines the resource as 'the end users or organisations your keys belong to' — which cleanly separates it from siblings like unkey_list_api_keys, unkey_list_roles, and unkey_get_identity.

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?

No when-to-use or when-not-to-use guidance: it never says to prefer unkey_get_identity for a single identity or unkey_list_api_keys for keys. Usage is only inferable from the name and the definition of 'identity'.

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