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

The annotations already establish that this is a non-read-only, non-destructive write, and the description's 'Log' aligns with that. The description adds only that the session is 'completed', implying a one-time insert rather than an in-progress update. It does not disclose additional behavioral traits such as record creation, idempotency, or return value, but annotations cover the safety profile.

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 sentence with no filler; the action and key inputs are front-loaded. Every phrase ('completed', 'duration', 'project', 'task link') earns its place.

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?

The description plus fully-described schema give an agent enough to invoke the tool: required duration_minutes, optional type, label, task_id, project_id, started_at. There is no output schema, but for a logging action the lack of return-value documentation is a minor gap. The six-parameter complexity is fully handled by the schema, so the description is not incomplete.

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?

All six parameters have descriptions in the schema (100% coverage), so the baseline is 3. The description's mention of 'duration, project, and task link' merely summarizes three of the parameters without adding new meaning. No compensation needed.

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 uses the specific verb 'Log' with the resource 'completed focus/pomodoro session', and lists the key attributes (duration, project, task link). This clearly distinguishes it from sibling logging tools like log_workout or log_nutrition by the session type. No ambiguity about what action is performed.

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 word 'completed' signals that the tool is for post-session logging rather than ongoing tracking, and naming the attributes tells the user what to supply. It doesn't explicitly name alternatives or exclusions, but the context is clear enough for an agent to route a focus-session logging request here. Sibling tools are mostly domain-specific loggers, so the description alone disambiguates.

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