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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value beyond that by disclosing data provenance — figures are computed from bank transactions linked to the project, not from journal entries — and that commitment summaries come from invoices, bills and expense claims.

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?

Three sentences, each earning its place: what is returned first, then when to use it, then how to supply the identifier. No filler or redundancy.

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?

With no output schema, the description carries the burden of describing the response and does so by naming the P&L components and the commitment summaries. Combined with the read-only annotations and full schema coverage, an agent has everything needed to invoke it 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?

Schema description coverage is 100%, so all three parameters are already documented, including the project_id preference and the ambiguity error on project_name. The description restates the id-vs-name routing but adds no syntax, format or edge-case 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 deal/project's mini P&L') and enumerates the components returned: income, costs by category, net margin, plus commitment summaries. The project scoping implicitly differentiates it from the company-wide get_profit_and_loss sibling, so an agent can route without opening the 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?

Gives concrete trigger phrasings ('how is project X doing', 'project profit', 'mini P&L for a project') and a situational cue (final report when a project completes), plus parameter routing (project_id if known, else project_name). No explicit 'when not to use' or named alternative such as get_profit_and_loss for entity-wide P&L, so it falls short of a 5.

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