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

readOnlyHint=true already establishes that this is a safe read, so the description's remaining burden is light. It adds the returned field families (status, dates, unit, rent) and the underlying endpoint, which is modest but real value; it says nothing about error behavior for a missing id.

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?

Two short fragments with no filler, and the resource description is front-loaded ahead of the endpoint reference. The telegraphic style leaves it a bit thin but nothing is wasted.

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?

Absent an output schema, listing the returned field families partially compensates, and readOnlyHint covers safety. However, for a tool sitting beside both arthur_get_tenant and arthur_list_tenancies, the omission of any disambiguation leaves an agent short of what it needs to pick correctly.

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?

With 100% schema coverage and a single required 'id' whose schema text already explains it is an Arthur numeric record id from the corresponding list tool, the baseline of 3 applies. The description adds no parameter 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?

A noun phrase enumerating the resource and its fields ('Tenancies, their status, dates, unit and rent details') plus an HTTP endpoint implies a single-record fetch by id, but no verb is stated. It does not differentiate this from the confusingly similar sibling arthur_get_tenant or from arthur_list_tenancies.

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 guidance, no prerequisites, and no reference to alternatives. An agent must infer that this is the by-id counterpart to arthur_list_tenancies and must guess the distinction from arthur_get_tenant on its own.

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