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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds the aggregation behavior (totals, sessions, project breakdown) but does not disclose other behavioral traits such as date inclusivity, timezone handling, or limits. 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?

A single, front-loaded sentence containing the verb, resource, return details, and date-range scope. Every word earns its place with no 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?

For a simple read-only tool with two optional, fully documented parameters and no output schema, the description adequately informs the agent of the return content and the date-range scope. Minor gaps like inclusive/exclusive date boundaries are not critical for its straightforward use case.

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%, with both 'from' and 'to' documented with formats and defaults. The description only restates the 'date range' concept without adding new meaning beyond the schema, so the baseline of 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 a specific verb and resource ('Get focus time summary') and specifies the return content: total minutes, sessions, and breakdown by project. This clearly distinguishes it from sibling tools like get_daily_entry or get_fitness_summary, though it does not name a sibling explicitly.

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 phrase 'for a date range' gives clear context on when to invoke this tool. However, it provides no exclusions or explicit alternatives among the many sibling tools, so it falls short of full routing guidance.

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