Zovo Focus Timer

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description still adds substantial behavior: it shortens or drops the standard long break to fit a whole block and says so, resolves ambiguous bare hours (5 after 14:00 read as 5pm, with a note), and defaults to America/New_York when date and zone are absent. It also enumerates the artifacts produced (clock times per block, total focus minutes, spare time, .ics, live timer).

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 dense sentences with the invocation trigger front-loaded before the mechanics and the limits. Despite covering a dozen parameters and an output contract, nothing reads as filler or repetition of 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?

For a 12-parameter, all-optional planning tool with an output schema, the description still covers the invocation scenario, the scheduling algorithm's key trade-off, output artifacts, and hard limits. Nothing an agent needs in order to call it correctly is missing.

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%, so the schema already documents the 12 parameters thoroughly and baseline would be 3. The description adds genuine meaning on top: the long-break shortening/dropping policy unless long-break settings were supplied, and the 24-hour cap tying to available_minutes' 1440 maximum.

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 ('fits the most whole focus blocks between the start and end time') and grounds it in concrete user phrasings like "I have 3 hours to study until 5pm". It never names its sibling show_focus_timer, and since it also returns 'a live timer for the plan', the boundary between planning and the timer tool is left implicit.

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?

Opens with an explicit trigger ('Use this when the user wants pomodoros fitted into a time window') and follows with three realistic utterance examples, then states exclusions: one window up to 24 hours, no calendar read/write, no multi-day study plans such as finals week. An agent knows both when to call it and when not to.

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

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and non-destructive, so the safety profile is known. The description still adds real value beyond that: hard limits (24 hours, 96 rounds), what is NOT supported (phone notifications, alarms when chat is closed, music), and DST-correct wall-clock times when start_time and time_zone are supplied. It does not mention persistence of the timer between turns, which is the main remaining behavioral unknown for a live UI tool.

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?

Trigger is front-loaded in the first clause, followed by mode examples, then outputs, then limits and exclusions in a deliberate order. It is dense but each clause carries information; the parenthetical example stacks in the opening sentence slow scanning slightly.

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 annotations covering safety, a 12-parameter schema at full description coverage, and an output schema handling return shape, the description fills exactly the remaining gaps: when to call it, what the user sees, hard limits, unsupported capabilities, and time-zone behavior. Nothing an agent needs to invoke it correctly is missing.

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 every parameter is already documented in the schema, which sets the baseline at 3. The description adds behavioral meaning for the start_time/time_zone pairing (every phase gets wall-clock times that survive daylight-saving changes) but repeats the mode and break examples already present in the schema.

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 ('show a live timer' with progress ring, controls) and enumerates the three concrete timer modes, so an agent knows exactly what is produced. It does not name the sibling plan_focus_session, leaving differentiation to the implied 'timer now' framing.

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?

Opens with an explicit trigger ('when the user wants a timer now') and closes with three concrete exclusions: future appointment reminders, duration questions, and unit conversions. It never names plan_focus_session as the alternative for planning ahead, so sibling routing is only partially covered.

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