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

Annotations already cover the safety profile (readOnlyHint=true), and the description adds real behavioral value by disclosing what the response contains (breaks and publish state) and the REST mapping. It stops short of noting auth requirements or error behavior, so it is not a 5.

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 core action and benefit, with the endpoint mapping trailing. No filler words and nothing redundant.

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-resource read tool with 100% schema coverage and annotations carrying the safety profile, this is nearly complete; calling out breaks and publish state partially compensates for the absent output schema. Only missing pieces are auth/error expectations, which are minor here.

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% – both shift_id and include_repeating_shifts_to are already well documented, including date-time formats. The description adds no parameter-level meaning 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?

The description states a specific verb and resource ('Fetch one shift by id') and even names the underlying endpoint (GET /2/shifts/{id}). The word 'one' plus the id requirement cleanly separates it from wheniwork_list_shifts without needing the sibling's 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?

Usage is implied by 'by id' – an agent can infer this is the single-record lookup versus list_shifts – but there is no explicit when-to-use/when-not guidance or mention of the alternative tools. Minimum viable.

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