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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful behavioral context not in the schema: the response bundles breaks, tags and a computed break total, and the underlying endpoint (GET /working_sessions?id=) is disclosed. It stops short of describing response shape or missing-id behavior.

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?

Two short sentences, front-loaded with the resource and then the returned payload. The trailing 'GET /working_sessions?id=.' is slightly awkward with the dangling '=' but gives a cheap endpoint mapping.

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?

With one parameter, no output schema, and a read-only tool, the description covers the essentials: what is fetched, by what key, and which fields come back. Only the absence of not-found/error behavior keeps it from being fully complete.

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 100% and the single id parameter is fully documented in the schema, so the baseline is 3. The description confirms the id refers to the working session (via the endpoint query string) but adds no format or edge-case detail beyond that.

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+resource: retrieves a single worked-time entry by id, listing the included sub-resources (breaks, tags, break total). This distinguishes it from the sibling papershift_list_time_trackings by scope (one vs. many), though it doesn't name that sibling explicitly.

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 'by id' phrasing implies this is the lookup path when you already have a time tracking id, and the sibling list tool covers browsing. But the description never states when to use this over papershift_list_time_trackings or mentions prerequisites.

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