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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety is covered structurally. The description adds nothing beyond that: no statement of what 'previous period' means (relative to what cutoff, fiscal vs calendar), no note on pagination or empty results, and no auth requirements.

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?

It is short, but the first sentence is duplicated verbatim and the remaining text is boilerplate about the operation ID and describe_operation. No front-loaded explanation of the resource, timeframe, or return shape; almost none of the text earns its place.

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?

A read tool with no output schema, an unconstrained nested query object, and 0% parameter documentation demands more from the description, not less. As written, an agent can only guess at the required path value and what the query object does, so the definition is materially incomplete.

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 0% and the description does not mention a single parameter. Both the required `leaseId` path param and the free-form nested `query` object (additionalProperties: {}) are completely undocumented, leaving the agent no idea what filters the query object accepts.

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 description does nothing but repeat the endpoint path 'GET /api/expenses/previous-period/:leaseId' twice, which restates the tool name rather than explaining it. An agent can infer it retrieves prior-period expenses for a lease, but only by parsing the URL, not from any stated purpose.

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 at all, despite numerous plausible alternatives in the sibling list (get_expenses_by_lease, get_expenses_period_overview, get_expenses_trends, get_expenses_contract_period_by_contract). The only actionable pointer is a generic 'describe_operation provides native request schemas', which addresses schema lookup rather than tool selection.

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