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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered structurally. The description adds nothing beyond that: it doesn't mention what happens on a missing/invalid id, permission requirements for staff records, or what fields come back — notable since there is no output schema.

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?

Five words with zero filler and the identifier key is front-loaded, so nothing is wasted. However, the brevity crosses into under-specification rather than efficient communication for a tool the agent must select among 18 siblings.

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?

The tool is structurally simple (1 required param, full schema coverage, read-only annotations), but with no output schema the description is the only place return shape could be described and it says nothing. Nor does it clarify the staff-vs-patient distinction that the sibling set makes necessary.

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 sole 'id' parameter is documented in the schema, so the baseline of 3 applies. The description only echoes 'by id' and adds no format, prefix, or sourcing detail 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?

The phrase 'One staff user by id' does signal a single-record retrieval keyed by id, which implicitly separates it from semble_list_users. But it is essentially a compressed restatement of the title 'Get a user (staff)' rather than a statement of action with scope or return semantics, leaving the agent to infer the verb.

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?

There is no explicit guidance on when to use this versus semble_list_users or semble_get_patient — the agent must infer the contrast purely from the word 'staff'. No prerequisites, no conditions, no stated alternatives.

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