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

With readOnlyHint=true already covering the safety profile, the description adds real value: it discloses that the response is JSON:API '{ data }' and that it contains PII, plus the underlying REST endpoint. It omits auth/permission requirements, but the PII disclosure is the meaningful behavioral signal here.

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?

A single compact sentence that front-loads the verb+resource, then appends return shape and endpoint reference with no filler. Every clause carries 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?

There is no output schema, so the description appropriately carries part of that burden by naming the JSON:API '{ data }' envelope and flagging PII. For a one-parameter read tool this is nearly complete, with only auth/permission context missing.

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% and the single case_id parameter is documented in the schema itself (including the case_... example). The description only restates 'by id' and adds no format or constraint detail beyond the schema, 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 ('Get a single case by id') and adds scope clarification ('a manual-review workflow item'), which distinguishes it from the sibling persona_list_cases. An agent can tell single-fetch from list without opening a schema.

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?

The 'by id' phrasing implies the retrieval-by-identifier use case, but there is no explicit when-to-use vs persona_list_cases guidance and no stated prerequisites or exclusions. Usage is inferable rather than directed.

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