Time report

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

Beyond the readOnlyHint/openWorldHint annotations, it discloses the data source (session transcripts, not a timesheet DB) and non-obvious computation semantics: agent time sums across parallel sessions while wall time counts each minute once. Those are exactly the details that change how an agent interprets the numbers, and they are not derivable from any structured field.

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 short sentences, front-loaded with what is measured, then the data source, then the intended use, then the two time-accounting rules. Every sentence carries distinct information and nothing is repeated from the schema.

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 five optional parameters, no output schema, and safety already covered by annotations, the description supplies the essential model: measurement unit, grouping, source, and the agent-vs-wall-time distinction. What it omits is the shape of the returned report (fields per task, how totals are grouped or sorted), which an agent must infer despite there being no output schema.

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 range/from/to/detail/project semantics are already documented in the schema itself. The description only adds the implicit grouping notion ('per project and task') and the period framing; it contributes no extra format, precedence, or defaults beyond the schema. 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 states precisely what is measured (time worked by the user and the agent), at what granularity (per project and task, i.e. branch or ticket), over what scope (a period), and from what source (session transcripts). No sibling tool overlaps with time reporting, so no explicit differentiation is needed, though the phrasing is a resource statement rather than a verb+resource construction.

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 two concrete example questions that select this tool ('how much time did I spend on X this week', 'what did I do this week'), which makes the intended call context unambiguous. There are no exclusion rules or named alternatives, but none of the sibling tools compete with this capability, so the guidance is practically complete.

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