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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the agent knows it's safe. The description adds useful behavioral context about what the summary contains (hours, budget, expenses, mileage) beyond the annotations, though it could mention that no data is modified.

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?

The description is two sentences with no wasted words. It immediately states the function and provides a concrete example, making it easy to parse.

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?

Given the presence of an output schema, the description does not need to explain return values. It covers the essential scope of the tool (single project summary with key metrics) and is complete for a read-only lookup tool.

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 coverage is 100% and the parameter 'name' is well-described as 'Project name to look up.' The description does not add additional semantics beyond identifying the parameter's role within the tool's purpose, which is adequate but not exceptional.

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 clearly states the tool provides a summary of a single project's hours logged vs. budget, billable hours, expenses, and mileage. It gives a concrete example question that demonstrates its specific purpose, distinguishing it from sibling tools that focus on individual metrics like time or expenses.

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?

The description implies usage for obtaining a holistic overview of a single project, but does not explicitly state when to use this tool over alternative summary tools like get_time_summary or get_expense_summary. The sibling list is provided, but guidance on when-not-to-use is absent.

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