Get time tracking entry

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

Annotations already declare this as read-only, idempotent, and non-destructive. The description adds valuable behavioral context: returns all fields by default, fields can narrow the response, and monetary values are integer cents. This goes beyond what annotations provide without contradicting them.

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 well-structured sentences: first states the primary action, second gives critical usage guidance, third notes a key data format detail. No wasted words, and the most important information is front-loaded.

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 single-entry fetch with rich annotations and full schema coverage, the description is largely complete. It clarifies return behavior ('all fields by default'), field narrowing, and monetary handling. Slight gaps include response structure details, but that is acceptable given no output schema and the tool's simplicity.

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?

The input schema covers all three parameters with detailed descriptions, so the schema handles the heavy lifting. The description adds minimal extra parameter meaning beyond restating that 'fields' narrows the response, but the schema already says this. Baseline 3 is appropriate.

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 'Fetch' with the resource 'one time tracking entry' and clarifies the key identifier 'numeric easybill ID'. It clearly distinguishes this from the sibling list tool by emphasizing single-entry retrieval.

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?

Explicitly directs users to use easybill_list_time_trackings first if only a name or number is known, naming the alternative tool. Also provides guidance on using the 'fields' parameter to narrow the response, covering the main decision point.

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