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

Annotations already communicate read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds a single-month query pattern, but it doesn't clarify period-vs-month precedence or the apparent FCF capability hinted by the example. No contradiction with annotations.

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 sentences, front-loaded with the core purpose. The second sentence is useful but the 'Feb free cash flow' example is slightly confusing and could have been replaced with a clearer P&L example, so it is not a perfect 5.

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 read-only tool with a full input schema, the description gives enough return content (revenue, expenses, net income) even though there is no output schema. It lacks explicit alternative routing and leaves the FCF example ambiguous, but the core call semantics are complete.

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%: month, period, companyId, and fiscal_year are all documented. The description only restates the month behavior and adds a natural-language example, so it adds no meaningful semantic beyond the schema – 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?

The description opens with a clear verb+resource: 'Get P&L summary' and lists the exact fields (revenue, expenses, net income), which separates it from cash position, transaction, or spend tools. It doesn't explicitly disambiguate against sibling financial tools, and the 'Feb free cash flow' example is an odd fit for a P&L tool, so it stops short of a 5.

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?

It gives one explicit usage rule: for single-month queries, provide the month parameter. However it never says when to prefer this tool over alternatives such as get_cash_position or get_monthly_trends, so the tool-selection guidance is only implied by the P&L scope.

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