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

Annotations already declare readOnlyHint=false and idempotentHint=false, but the description adds real value beyond them: user_id is silently ignored for non-admins, every call creates a duplicate entry, and nothing is dispatched to anyone. Those are consequences an agent could not infer from the annotations alone.

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?

Four tight sentences, front-loaded with the WRITE marker and endpoint, then the prerequisites, then the caveats. No filler; each clause carries actionable 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?

Covers the mutation, its required inputs, the admin caveat, and the duplicate-creation behavior. With no output schema, it is silent on what the call returns (e.g. the new entry id), which is the only notable gap for a create operation.

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 task_id, hours, and user_id semantics are already documented. The description largely restates the schema (decimal hours, admin-only user_id) and only adds the pointer to tick_list_tasks for obtaining task_id, 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?

States a specific verb and resource ('log a new time entry on a task') plus the endpoint, which distinguishes it cleanly from the sibling tick_update_entry. An agent knows exactly what operation this performs without opening the 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?

Points the agent to tick_list_tasks to obtain the required task_id, and 'Creates a new entry every call' implies the update path for existing entries. It never explicitly names tick_update_entry as the alternative for correcting an entry, so routing guidance is clear but not complete.

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