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

Annotations already declare readOnly=false, idempotent=false, destructive=false and openWorld=true, so the 'WRITE:' label largely repeats structured data. The description adds nothing about the non-idempotency consequence (repeat calls create duplicate entries) or how date, start_time, end_time and minutes relate to each other—context an agent would need to book time correctly.

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?

One compact sentence with the mutation signal and the required-field precondition front-loaded; nothing is padded. It is arguably too terse for a 9-parameter write tool, but that is a completeness issue rather than wasted text.

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?

A 9-parameter write tool with no output schema and only 56% schema coverage needs more than a single clause. The description leaves unanswered whether end_time can be omitted when minutes is supplied, what date does when start_time is required, and what the tool returns.

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 only 56% and 9 parameters exist, so the description should compensate. It instead repeats the three required fields already marked required in the schema and says nothing about comment, article_id, billable_minutes, or the date-vs-start_time-vs-minutes relationship the schema only partially documents.

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 ('book a work time entry on a project') and names the three required fields, so an agent can tell it apart from the sibling list_time_entries. It stops short of naming alternatives explicitly, but the create-vs-list distinction is unambiguous.

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 'WRITE:' prefix implies this is the mutation path as opposed to reading entries, and the required-field callout gives a minimum bar for invocation. No explicit when-not-to-use guidance, no mention of duplicate handling, and the sibling list_time_entries is never named.

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