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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is partly covered. The description still adds real value by stating the consequence — 'It changes the employee's recorded hours and balance' — which tells the agent this is a balance-affecting mutation, not an isolated record. It does not mention required permissions or what happens on duplicate submission (implied only by the non-idempotent hint).

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 compact sentences with the write marker and core action front-loaded, followed by consequence and id sources. There is no filler and every sentence carries distinct information.

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 six-parameter write tool with a fully documented schema and no output schema, the description covers action, impact, and id provenance well. The remaining gap is the result of the call — whether it returns the created working session or only a status — which matters for a non-idempotent mutation an agent may want to verify afterward.

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 all six parameters (including manual_pause as 'Break length in minutes' and ISO 8601 formats) are already documented. The description restates the same fields (start, end, break minutes, location, working area) without adding format, range or default guidance beyond the schema, so the 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?

Starts with an explicit 'WRITE:' verb marker and a specific resource: a worked-time entry for an employee with start, end and break minutes, in a location and working area. The phrase 'after the fact' distinguishes retroactive entry from live clocking, so an agent can separate it from the other create_* siblings without opening a schema.

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?

Gives clear context for when to use it (retroactive entry) and tells the agent exactly how to source the three foreign-key ids from papershift_list_locations, papershift_list_working_areas and papershift_list_users. It stops short of naming alternatives or exclusions, e.g. when to prefer papershift_confirm_time_tracking to approve a pending session instead.

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